0
question_answer1) Give the difference between a cation and an anion.
question_answer2) Write the chemical formula of the compound zinchydroxide.
question_answer3) Calculate the formula unit mass of . [Atomic mass of Na = 23 u, H = 1 u, C = 12 u,O=16u]
question_answer4) Calculate the formula unit mass of . [Atomic mass of Na =23 u, C =12u, O = 16 u]
question_answer5) Give an example of a triatomic molecule of anelement.
question_answer6) Which number is represented by 1 mole?
question_answer7) Calculate the number of moles in 71g of chlorine.[Atomic mass of Cl = 35.5]
question_answer8) An element Z has a valency of 3. What is theformula of oxide of Z?
question_answer9) Calculate the molecular mass of. [Atomic mass of H=1u,S=32u, O =16u]
question_answer10) How many atoms are present in 0.012kg of C-12? What is the name given to this constant?
question_answer11) Calculate the molar mass of sugar [Atomic mass of C =12u, O =16u, H=1u]
question_answer12) Define atomicity.
question_answer13) How many atoms are present in onemolecule of ozone?
question_answer14) Write the names of the followingcompounds. (a) (b)
question_answer15) Name the metal which is used formaking pressure cooker and aeroplane.
question_answer16) What is an atom?
question_answer17) What is a molecule?
question_answer18) What is the law of constant proportions?
question_answer19) What is the formula of calcium sulphate?
question_answer20) Which is an ionic compound among and?
question_answer21) What is the chemical symbol for nitrogen sgas?
question_answer22) What is the chemical symbol for sodium?
question_answer23) Is argon monoatomic or diatomic?
question_answer24) What is the value of Avogadro's constant?
question_answer25) What is the chemical symbol for hydrogen gas?
question_answer26) If we have 4 g of and 8 g of then will it contain same number of atoms or same number of moles?
question_answer27) How many litres do and at STP contain?
question_answer28) Which is octa-atomic, carbon or sulphur?
question_answer29) Which of these contains more number of molecules; 1 g of or 1g of?
question_answer30) Which element is considered as the lightest element?
question_answer31) What is the mass of sodium in 58.5 g of NaCI?
question_answer32) What is the chemical formula of ammoniumphosphate?
question_answer33) What is the combining capacity of an element called?
question_answer34) What is the molecular formula of aluminium hydroxide?
question_answer35) What are the correct formulae of sodium sulphide and sodium sulphite :NaS, or?
question_answer36) If an element X has its valency equal to 3,what will be its formula with carbonate ion?
question_answer37) How many moles does 24 g of Mg contain?
question_answer38) Which among the following is the correct symbol of gold-Gd, Gl or Au?
question_answer39) How many litres does 2 moles of gas at STP contain?
question_answer40) What is the molecular weight of
question_answer41) What is the formula unit mass of ?
question_answer42) Which is a true triatomic molecule among these?, or ?
question_answer43) What is the molar mass of ?
question_answer44) Calculate the mass of 3.011 x 1023 N atoms.[Atomic mass of nitrogen = 14]
question_answer45) Calculate the number of moles for the following. (a) 64 g of oxygen atom (b) 24.088 x 1021 number of oxygen atoms[Atomic mass of 0 = 16u]
question_answer46) Calculate the mass of 1 molecule of oxygen gas. [Atomic mass of 0 = 16u,]
question_answer47) (a) Write the formula of the compound formed by the ions and .
question_answer48) Write the cations and anions present (if any)in the following compounds. (a) (b) (c) (d)
question_answer49) An element Y has a valency of 4 write the formula for its
question_answer50) What is the fraction of the mass of water due to neutrons?
question_answer51) Write the molecular formulae of all the compounds that can be formed by the3M combination of the following ions
question_answer52) (a) Calculate the number of moles of magnesium present in a magnesium ribbon weighing 12g. Molar atomic mass of magnesium is 24g (b) Calculate the formula unit mass of .
question_answer53) The mass of a single atom of an element isCalculate its atomic mass.
question_answer54) Give the names of any two elements present in the following compounds. Baking powder. Common salt. Sulphuric acid
question_answer55) (a) Give one word for the following. (i) Positively charged ion (ii) A group of atoms carrying a charge (b) Mention any two important rules for writing a chemical formula.
question_answer56) Calculate the number of atoms in (a) 8 g of molecules (b) 0.1 mole of C atoms[Atomic mass of 0 = 16,
question_answer57) Calculate the number of moles for the following. (a) 84 g nitrogen atom (b) 8.066 x 1023 number of N atoms [Atomic mass of N = 14]
question_answer58) What is an ion? Write the symbol of calcium ion and aluminium ion.
question_answer59) A saline solution contains 40 g of common salt (NaCI) and 320 g of water. Calculate the (a) number of moles of common salt present in the solution. (b) number of molecules of water present in the solution.
question_answer60) If 12 g of C is burnt in the presence of 32 g of , how much will be formed?
question_answer61) Calculate the number of moles in 8.5 g of. [Atomic mass of N = 14, H = 1]
question_answer62) Calculate the number of molecules in 11gof. [Atomic mass of C and O are 12and 16 respectively]
question_answer63) Calculate the number of molecules in 4 g of methane. [Atomic mass of C = 12 u, H = 1u]
question_answer64) What are the two laws under the law of chemical combination?
question_answer65) (a) Who gave the law of conservation of mass? (b) State the law of conservation of mass.
question_answer66) Which law is also known as law of definite composition? Also state the law.
question_answer67) What is the difference between sodium atom and sodium ion?
question_answer68) Name some elements which show variable valencies.
question_answer69) Which law is also known as law of indestructibility of matter? Why?
question_answer70) (a) What is the relative atomic mass of an element? (b) What is the average atomic mass of hydrogen?
question_answer71) How do molecules exist in a chemical reaction?
question_answer72) Write the chemical formulae of (a) calcium hydroxide (b) potassium sulphate
question_answer73) Calculate the mass of one atom of oxygen. (Atomic mass of O = 16u)
question_answer74) Convert 10g of oxygen gas into moles. (Atomic mass of O = 16 u)
question_answer75) Convert into mole (a) 20 g of water (Atomic masses of hydrogen and oxygen are 1 and 16 respectively) (b) 22 g of carbon dioxide (Atomic masses of carbon and oxygen are 12 and 16 respectively)
question_answer76) During photosynthesis a six carbon atom molecule glucose is formed. Calculate its molecular mass. (Atomic mass C= 12.0 u, H = 1.0 u, 0 = 16.0 u)
question_answer77) Calculate the molar mass of the following compounds. (a) Lead sulphate (b) Calcium phosphate [Given atomic masses of various elements Ca = 40, S = 32, 0 = 16, Pb = 207, P = 31]
question_answer78) Write the formulae of (a) sodium chloride (b) aluminium oxide (c) ammonium sulphate
question_answer79) Write the chemical formulae, using criss-cross method. (a) Magnesium bicarbonate (b) Barium nitrate (c) Potassium nitrate
question_answer80) (a) Write chemical formulae of the following compounds (i) Aluminium nitride (ii) Ammonium phosphate (b) Name an element which shows a variable valency. Write the formulae of its two chlorides.
question_answer81) Calculate (a) the mass of molecules of carbon dioxide (b) the number of molecules of 0.25 mol of. (c) the formula unit mass of . [Atomic mass of Na = 23 u, S = 32 u, 0 = 16u, ]
question_answer82) Define the term mole. Calculate the number of moles in (a) 3.011 x 1023 atoms of C (b) 32 g of oxygen gas [atomic mass of 0 = 16 u and C = 12 u]
question_answer83) Find the number of atoms in 120 g of calcium and 120 g of iron. Which one has more number of atoms and how much is the difference? [Atomic mass of Ca = 40 u, Fe = 56 u]
question_answer84) Find (a) number of molecules of 90 g of (b) number of moles in 19 g of (c) formula unit mass of [Atomic mass unit Al = 27u,C = 12u, ]
question_answer85) Classify each of the following on the basis of their atomicity. (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l)
question_answer86) An activity was conducted in a classroom where students held play cards with symbols and valency of the elements separately. Each student held two play cards, one with the symbol in the right hand and other with the valency in the left hand. Read the above passage and answer the following questions. (a) Which play cards will be required for the formation of sodium chloride (both symbol as well as valency)? (b) Which qualities are required in the student to perform such a group activity? (Value Based Question]
question_answer87) Which of the following symbols of elements are incorrect? Give their correct symbols. (a) Cobalt CO (b) Carbon c (c) Aluminium AL (d) Helium He (e) Sodium SO [NCERT Exemplar]
question_answer88) State the number of atoms present in each of the following chemical species. (a) (b) (c) (d) CO
question_answer89) Write the molecular formulae for the following compounds. (a) Copper (II) bromide (b) Aluminium (III) nitrate (c) Iron (III) sulphide (d) Mercury (U) chloride (f) Magnesium (II) acetate
question_answer90) The mass of a single atom of M is g. What is its atomic weight? What would this element be? Check table for possible answer.
question_answer91) (a) Find the mass of one molecule of water. (b) If 16.26 mg of a sample of an element X contains 1.66 x 1020 atoms. What is the atomic mass of the element X!
question_answer92) Two students of class IX, Kaveri and Nalini, were asked to take 5.3 g of sodium carbonate and 6 g of ethanoic acid to make 2.2 g of carbon dioxide, 0.9 g of water and 8.2 g of sodium ethanoate. Kaveri followed the instructions but Nalini took the chemicals without measuring their amounts. Read the above passage and answer the following questions (a) Whose activity do you think will be in agreement with the law of conservation of mass? (b) State the law of conservation of mass. (c) Whose method do you like and why?
question_answer93) Give the chemical formulae for the following compounds and compute the ratio by mass of the combining elements in each one of them. (a) Ammonia (b) Carbon dioxide (c) Hydrogen chloride (d)Aluminium fluoride (e) Magnesium sulphide
question_answer94) Give the formulae of the compounds formed from the following sets of elements (a) Calcium and fluorine (b) Hydrogen and sulphur (c) Nitrogen and hydrogen (d) Carbon and chloride (e) Sodium and oxygen (f) Carbon and oxygen
question_answer95) Calculate the number of molecules of sulphur present in 32 g of solid sulphur.
question_answer96) Calculate the number of aluminium ion present in 2 g of aluminium oxide.
question_answer97) Find out the percentage composition of sulphuric acid
question_answer98) Find out the ratio by mass of the combining element in the following compounds. (a) (b) (c)
question_answer99) Write the chemical formulae and calculate the molecular mass of the following. (a) Common salt (b) Sodium carbonate (c) Caustic soda
question_answer100) 6 g of a sample of a compound having boron and oxygen was found on analysis to contain2 g of boron and 4 g of oxygen. Calculate the percentage composition of the compound.
question_answer101) 12 g of He is equal to how many atoms?
question_answer102) Which would weigh the more, 2 moles of or 10 moles of ?
question_answer103) Which has more number of atoms, 18 g of or 18 g of ?
question_answer104) If 3.42 g of sucrose is dissolved in 18 g of water in a beaker, then what will be the number of oxygen atoms in the solution?
question_answer105) The visible universe is estimated to contain1022 stars. How many moles of stars are present in the visible universe?
question_answer106) Cinnabar (HgS) is a prominent ore of mercury. How many grams of mercury are present in 225 g of pure HgS? [Molar mass of Hg and S are 200.6 g and 32 g respectively].
question_answer107) A sample of vitamin C is known to contain2.58 x 1024 oxygen atoms. How many moles of oxygen atoms are present in the sample?
question_answer108) Verify by calculating that (a)5moles of and 5 moles of do not have the same mass. (b) 240 g of calcium and 240 g of magnesium elements have a mole ratio of 3 : 5.
question_answer109) What are ionic and molecular compounds? Give examples.
question_answer110) Find the mass of each one of the following. (a) 1 mole of water (b) 1 mole of ethanol (c) 1 mole of glucose (Atomic mass of H = 1u, 0 = 16u, C = 12u)
question_answer111) Ravi prepared a solution of sodium chloride by mixing 5.85 g of salt in 1 litre of water. Find (a) molar mass of sodium chloride. (b) number of moles of sodium chloride dissolved. (Atomic masses of sodium and chlorine are23 u and 35.5 u respectively). (c) Concentration of the sodium chloride Solution.
question_answer112) Calculate the molecular mass of the following compounds (a) (b) (c)(Atomic mass of H = 1 u, 0 = 16 u, S = 32 u, C=12u)
question_answer113) (a) What is the mass of 0.5 mole of? Given atomic mass of N = 14 u, atomic mass of H=1u. (b) Calculate the number of particles in 31 g of molecules. Atomic mass of P = 31u. (c) Find the number of moles in 87 g of. (Atomic masses of K = 39 u, S = 32 u, 0=16 u)
question_answer114) An element A exists as diatomic gas in nature which is relatively inert and forms78% of earth's atmosphere. (a) Identify the gas and write its molecular formula. Write the formulae of its nitrite and nitrate ions. (b) How many moles of this gas would contain12.044 x 1023 atoms of this element? (Avogadro's no. = 6.022 x 1023) (c) Calculate the molecular mass of (a)and (b) (Given atomic masses N == 14 u, 0 = 16 u, H=1u) (a) Define Avogadro's number. (b)Show that 100 g of water and 100 g of carbon dioxide are not equal in number of moles. Molecular masses of water and carbon dioxide are 18 u and 44 u respectively. (c) Calculate the number of molecules present in the 100 g for both water and carbon dioxide.
question_answer115) (a) Calculate the number of atoms of hydrogen present in one dozen molecule of hydrogen gas. Convert the given number of hydrogen in terms of number of moles. (b) If hydrogen combines with oxygen in the ratio of 1 : 8 by mass to form water, how many moles of oxygen would be required for the given amount of hydrogen gas? (Atomic mass of H= 1.0 u,0= 16.0 u)
question_answer116) Calculate the following quantities in 5.6 g of nitrogen [Atomic mass of N = 14 u] (a) Number of moles of (b) Number of molecules of (c) Number of atoms of nitrogen. Or A vessel contains 5.6 grams of gas. Calculate the number of moles of gas, number of nitrogen molecules and number of nitrogen atoms if the atomic mass of and per mole.
question_answer117) (a)Calculate the number of moles in 112 g of iron. (b) Calculate the mass of 0.5 moles of sugar . (c) Define the term molecular mass. (d) Determine the molecular mass of [Atomic mass of Zn = 65 u, S = 32 u, 0 = 16 u], (e) Calculate the number of molecules of carbon dioxide, present in 4,4 g of .
question_answer118) (a)(i)What mass of silver nitrate will react with 5.85 g of sodium chloride to produce 14.35 g of silver chloride and 8.5 g of sodium nitrate? (ii)On what law is the above reaction based and state the law? (b)Calculate the number of molecules in 50 g of . (c)Calculate the mass of 0.5 moles of nitrogen gas, (d) Calculate the number of molecules in 50 g of NaCl. [Atomic mass of Ca = 40 u, C =12 u, 0=16, u, N= 14 u, Na=23u, Cl =35, 5u,
question_answer119) Shashank was quite confused when he was taught mole concept in class. Next day, he went to the market with his father to buy fruits. His father bought one dozen apples, one dozen banana, one dozen oranges and one dozen pears. Fruit-seller gave them fruits according to their masses in kg. On observing their respective masses, Shashank understood the mole concept clearly. Read the above passage and answer the following questions. (a)What is mole concept? (b)How many pieces come in one dozen? (c) What made Shashank understand mole concept? (d) What is Avogadro constant? (e) What are the values of Shashank and his father?
question_answer120) Calcium chloride when dissolved in water dissociates into its ions according to the following equation. Calculate the number of ions obtained from when 222 g of it is dissolved in water.
question_answer121) The mass of one steel screw is 4.11 g. (a) Find the mass of one mole of these steel screws. (b) Compare this value with the mass of the Earth . Which one of the two is heavier and by how many times?
question_answer122) Find the ratio by mass of the combining elements in the following compounds. (a) (b) (c) (d) (e) (f)
question_answer123) Fill in the missing data in the following table. Species/Property Na atom Number of moles 2 - - 0.5 Mass 36 g - 115 g -
question_answer124) On Ishita's birthday, her mother Indu decided to prepare a cake at home. For preparing cake, she added some quantity of baking powder tomaida. Baking powder contains baking soda or sodium bicarbonate. Ishita asked her mother, the use of this powder. Then she told the use of this powder. Read the above passage and answer the following questions (a) Give the formula of baking soda. (b) Name the elements present in baking soda. (d) What is the ratio by mass of the combining elements in baking soda? (d) What is the ratio of atoms of different elements present in baking soda? (e) What are the values associated with Indu and lshita? [Value Based Question]
question_answer125) Fill in the blanks (a) In a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is called .... (b) A group of atoms carrying a fixed charge on them is called .... (c) The formula unit mass of is (d) Formula of sodium carbonate is ... and that of ammonium sulphate is ....
question_answer126) Write the formulae for the following and calculate the molecular mass for each one of them. (a) Caustic potash (b) Baking soda (c) Limestone (d) Caustic soda (e) Ethanol (f) Common salt
question_answer127) Raunak took 5 moles of C atoms in a container and Krish also took 5 moles of sodium atoms in another container of same weight. Whose container is heavier? Whose container has more number of atoms?
question_answer128) Raghu and Vansh were performing an activity related to conservation of mass in chemistry lab of their school. They mixed a solution of barium chloride and sodium sulphate. Raghu suggested that as they already knew the amount of both compounds taken by them, they need not to measure the amount of final solution. On the contrary, Vansh insisted to measure the amount of final solution, which had barium sulphate and sodium chloride. [Atomic massof ions ] Read the above passage and answer the following questions (a) Determine the molecular mass of (i) barium chloride (ii) barium sulphate (iii) sodium sulphate (iv) sodium chloride (b) Comment on Vansh's insistence toComplete the activity. [Value Based Question]
question_answer129) Give an account of the combining elements and atomicity of the given compounds. (a) (b) (c) (d) (e)
question_answer130) Write down the formulae of (a) sodium phosphate (b) zinc oxide (c) aluminium borate (d) barium oxide (e) calcium hydroxide
question_answer131) (a) How do we express number of particles in terms of moles? (b) Calculate the number of moles of sodium in a sample containing 1020 atoms of sodium. (c) How do we express mass of a substance in terms of moles? (d) Calculate the number of moles in (i) 56 g of He (ii) 23gofNa
question_answer132) What are the important features of Dalton' s atomic theory?
question_answer133) is an air pollutant released during burning of fossil fuels and from automobile exhaust'. (a) Write the names of elements present in this gas. (b) What are the valencies of sulphur in and ? (c) Find out the number of molecules in 5moles of . (d) Calculate the number of moles in 320 g of gas. (e) Calculate the molar mass of 10 moles of sodium sulphite. (Given : Atomic masses of S = 32 u,= 16 u, Na = 23 u, NA = 6.022x 1023 per mole)
question_answer134) (a) One mole of carbon atoms weighs 12 g. Find the mass of 1 atom of carbon in grams. (Avogadro's number = 6.022 x 1023per mole) (b) Calculate the mass of the following. (i) 0.5 mole of gas (ii) 0.2 mole of O atoms (iii) 4 moles of aluminium atom(Given N =14 u; 0 = 16 u; Al =27 u ;Avogadro's no. = 6.022x 1023 per mole)
question_answer135) (a) Which has more number of atoms? (i) 10 g of nitrogen (ii) 10 g of ammonia ? (b) Calculate the total number of moles in0.585 g of sodium chloride. (Atomic mass of N = 14 u, H = 1 u, Cl = 35.5
question_answer136) Name the Indian philosopher who proposed the theory of matter.
question_answer137) What is Dalton?
question_answer138) Which postulate of Dalton's atomic theory is a result of the law of conservation of mass?
question_answer139) Which postulate of Dalton's atomic theory can explain the law of definite proportions?
question_answer140) Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?
question_answer141) Find the ratio by mass of the elements present in molecule of hydrogen sulphide . Given that, atomic mass S = 32, H = 1.
question_answer142) Why is it not possible to see an atom with naked eyes?
question_answer143) Give an example of a triatomic molecule of an element.
question_answer144) Define atomicity.
question_answer145) Write the atomicity of the following molecules: (i) (ii)
question_answer146) What is the difference between and 2H?
question_answer147) What is an ion? Give one example.
question_answer148) What are polyatomic ions? Give examples. Ans. The ions which consist of more than one atom are called polyatomic ions. are examples of polyatomic ions.
question_answer149) Give one word for the following: (i) Positively charged ion (ii) A group of atoms carrying a charge
question_answer150) What is wrong in saying 'one mole of nitrogen'?
question_answer151) What is meant by the term chemical formula?
question_answer152) 'Dalton's atomic theory is contradicted by the formula of sucrose .' Justify the statement.
question_answer153) Chemical formula of a metal sulphate is . What will be the formula of its chloride?
question_answer154) An element 'A' has valency +3, while another element 'B' has valency -2. Give the formula of their compound formed when 'A' reacts with 'B'.
question_answer155) Valency of an element X is 3. Write the chemical formula of its oxide.
question_answer156) How many times heavier is one atom of carbon than one atom of oxygen?
question_answer157) In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium ethanoate. Show that these observations are in agreement with the law of conservation of mass. Sodium carbonate + ethanoic acid Sodium ethanoate + carbon dioxide + water
question_answer158) Write the molecular formulae for the following compounds: (a) Copper (II) bromide (b) Aluminium (III) nitrate (c) Calcium (II) phosphate (d) Iron (III) sulphide (e) Mercury (II) chloride (f) Magnesium (II) acetate
question_answer159) Write chemical formulae of (i) Hydrogen sulphide (ii) Iron (II) chloride.
question_answer160) Write the molecular formulae of all the compounds that can be formed by the combination of following ions
question_answer161) Write the cations and anions present (if any) in the following compounds: (a) (b) (c) (d)
question_answer162) Which of the following symbols of elements are incorrect? Give their correct symbols. (a) Cobalt CO (b) Carbon c (c) Aluminium AL (d) Helium He (e) Sodium So
question_answer163) Calculate the mass percentage of oxygen present in the following compounds and state the law of chemical combination associated. Given, H = 1,0= 16. Water and (ii) Hydrogen peroxide
question_answer164) Write the chemical formula and chemical name of the following compounds: (a) Baking powder (b) Quick lime (c) Washing soda
question_answer165) Give the names of elements present in (a) Quick lime (b) Hydrogen bromide (c) Baking powder (d) Potassium sulphate
question_answer166) We cannot say an atom of water. Why?
question_answer167) Which of the following are tri-atomic and tetra-atomic molecules?
question_answer168) Classify each of the following on the basis of their atomicity. (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) (k) (l)
question_answer169) How many atoms are present in a (i) molecule and (ii) ion?
question_answer170) Write down the formulae of (i) Sodium oxide (ii) Aluminium chloride (iii) Sodium sulphide (iv) Magnesium hydroxide (v) Copper nitrate (vi) Calcium carbonate.
question_answer171) Write down the names of compounds represented by following formulae (i) (ii) (iii) (iv) (v)
question_answer172) An element 'X' has a valency 3(+): (a) Write the formula of its phosphide (b) Write the formula of its carbonate.
question_answer173) An element 'Z' forms the following compound when it reacts with hydrogen, chlorine, oxygen and phosphorous. and (a) What is the valency of element 'Z'? (b) Element 'Z' is metal or non-metal?
question_answer174) Write the formula of the compounds formed by the following ions. (a) and (b) and
question_answer175) Calculate the molecular mass of the following: (a) (b) (c)
question_answer176) Differentiate between the actual mass of a molecule and gram molecular mass.
question_answer177) Calculate the formula mass of sodium carbonate
question_answer178) Calculate the formula unit masses of and . [Atomic mass of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, 0 = 16 u]
question_answer179) 23. Calculate the mass of one atom of hydrogen atom.
question_answer180) What are ionic and molecular compounds? Give examples.
question_answer181) Calculate the number of aluminium ions in 0.051 g of aluminium oxide. [Atomic mass of Al = 27 u]
question_answer182) Calculate the number of molecules present in 0.5 mole of water.
question_answer183) Calculate the number of molecules of sulphur present in 16 g of solid sulphur.
question_answer184) Give three significance of mole.
question_answer185) How many (a) molecules (6) hydrogen atoms (c) oxygen atoms are there in 0.5 mol of water?
question_answer186) How many moles are present in 4 g of sodium hydroxide?
question_answer187) If one mole of carbon atoms weigh 12 g, what is the mass (in gram) of 1 atom of carbon?
question_answer188) Which has more number of atoms, 100 g of sodium or 100 g of iron? [Given: Atomic mass of Na = 23 u, Fe = 56 u]
question_answer189) Calculate the molar mass of the following substances: (a) Ethyne, (b) Sulphur molecule, (c) Phosphorus molecule, (Atomic mass of phosphorus =31) (d) Hydrochloric acid, HCl (e) Nitric acid,
question_answer190) What is the mass of (a) 0.2 mole of oxygen atoms? (b) 4 mol of aluminium atoms (Atomic mass of aluminium = 27)? (c) 10 mol of (sodium sulphite)? (d) 1.50 mol of ion?
question_answer191) Convert into mole (i) 12 g of oxygen gas (ii) 20 g of water (in) 22 g of carbon dioxide.
question_answer192) Calculate the number of moles in 3.011 X 1023 molecules of nitrogen.
question_answer193) Calculate the mass per cent of each element of sodium chloride in one mole of it.
question_answer194) A sample of ammonia weighs 3.00 g. What mass of sulphur trioxide contains the same number of molecules as are in 3.00 g ammonia?
question_answer195) Carbon dioxide produced by action of dilute hydrochloric acid on potassium hydrogen carbonate is moist whereas that produced by heating potassium hydrogen carbonate is dry. What would be the difference in the composition of carbon dioxide in the two cases? State the associated law.
question_answer196) How many atoms would be present in a black dot marked on the paper with graphite pencil as a full stop at the end of a sentence. [Given mass of a dot ]
question_answer197) Calculate the number of particles in each of the following: (a) 46 g of Na atom (b) 8 g of molecules (c) 0.1 moles of carbon atom
question_answer198) Calculate the molecular masses of (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) [Atomic mass of H = 1 u, 0 = 16 u, Cl = 35.5 u, C = 12 u, N = 14 u]
question_answer199) Arrange the following in order of decreasing masses: (i) 1023 molecules of gas (ii) 0.1 g atom of silver (iii) 1 gram of carbon (iv) 0.1 mole of (v) 102 atoms of calcium. (Given Atomic masses: Ag = 108 u, S = 32 u, N = 14 u, Ca = 40 u)
question_answer200) Calculate the number of aluminium ions in 0.056 g of alumina
question_answer201) Calculate the mass per cent of each element present in the molecule of calcium carbonate.
question_answer202) Verify by calculating that (a) 5 moles of and 5 moles of do not have the same mass. (b) 240 g of calcium and 240 g of magnesium elements have a mole ratio of 3:5.
question_answer203) Find the ratio of mass of the combining elements in the following compounds:
question_answer204) Calcium chloride when dissolved in water dissociates into its ions according to the following equation. Calculate the number of ions obtained from when 222 g of it is dissolved in water.
question_answer205) What is a mole? What is the unit of mole? How many molecules are there in a certain mass of a substance?
question_answer206) The difference in the mass of 100 moles each of sodium atoms and sodium ions is 5.48002 g. Compute the mass of an electron.
question_answer207) The mass of one steel screw is 4.11g. Find the mass of one mole of these steel screws. Compare this value with the mass of the Earth Which one of the two is heavier and by how many times ?
question_answer208) Compute the number of ions present in 5.85 g of sodium chloride.
question_answer209) A gold sample contains 90% of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?
question_answer210) Compute the difference in masses of one mole each of aluminium atoms and one mole of its ions. (Mass of an electron is 9.1 X 10-28 g). Which one is heavier?
question_answer211) A silver ornament of mass 'w' gram is polished with gold equivalent to 1% of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.
question_answer212) A sample of ethane gas has the same mass as 1.5 X 1020 molecules of methane . How many molecules does the sample of gas contain?
question_answer213) In photosynthesis, 6 molecules of carbon dioxide combine with an equal number of water molecules through a complex series of reactions to give a molecule of glucose having a molecular formula . How many grams of water would be required to produce 18 g of glucose? Compute the volume of water so consumed assuming the density of water to be
question_answer214) 3.42 g of sucrose are dissolved in 18 g of water in a beaker. Find the number of oxygen atoms in the solution. Calculate the ratio between the mass of one atom of hydrogen and mass of one atom of silver.
question_answer215) A colourless liquid is thought to be a pure compound. Analysis of three samples of the material yield the following results. Mass of Sample Mass of Carbon Mass of Hydrogen Sample 1 1.0 g 0.862 g 0.133 g Sample 2 1.549 g 1.335 g 0.214 g Sample 3 0.988 g 0.852 g 0.136 g Could the material be a pure compound?
question_answer216) A big drop of water has volume 1.0 mL. How many molecules of water are there in this drop. If the density of water is 1g/mL?
question_answer217) What is the fraction of the mass of water due to neutrons?
question_answer218) You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without tasting?
Please Wait you are being redirected....
You need to login to perform this action.You will be redirected in 3 sec
OTP has been sent to your mobile number and is valid for one hour
Your mobile number is verified.