-
question_answer1)
What is the atomic weight of an element X for which a sample containing \[1.58\times {{10}^{22}}\] atoms weigh 1.05 g?
A)
28 g done
clear
B)
20 g done
clear
C)
40 g done
clear
D)
23 g done
clear
View Solution play_arrow
-
question_answer2)
When \[Fe{{S}_{2}}\] is burnt in air, it converts into \[F{{e}_{2}}{{O}_{3}}.\] The change in percentage by weight of iron in the process is (Fe = 56)
A)
23% increase done
clear
B)
12% decrease done
clear
C)
12% increase done
clear
D)
no change done
clear
View Solution play_arrow
-
question_answer3)
An analysis of organic compound gave 74.0% C, 8.65% of H and 17.3% N. What is the empirical formula of compound?
A)
\[{{C}_{5}}{{H}_{8}}N\] done
clear
B)
\[{{C}_{10}}{{H}_{12}}N\] done
clear
C)
\[{{C}_{5}}{{H}_{7}}N\] done
clear
D)
\[{{C}_{10}}{{H}_{14}}N\] done
clear
View Solution play_arrow
-
question_answer4)
How many grams of \[CaO\] are required to neutralize 852 g of \[{{P}_{4}}{{O}_{10}}\]?
A)
1008 g done
clear
B)
108 g done
clear
C)
1800 g done
clear
D)
3600 g done
clear
View Solution play_arrow
-
question_answer5)
Calcium carbonate reacts with aqueous HCl to give \[CaC{{l}_{2}}\] and \[C{{O}_{2}}\] according to the reaction, |
\[CaC{{O}_{3}}(s)+2HCl(aq)\to \]\[CaC{{l}_{2}}(aq)+C{{O}_{2}}(g)+{{H}_{2}}O(l)\] |
In this reaction, 250 mL of 0.76 M HCI reacts with 1000 g of \[CaC{{O}_{3}}.\] Calculate the mass of \[CaC{{l}_{2}}\] formed in the reaction. |
A)
11.1 g done
clear
B)
10.54 g done
clear
C)
5.25 g done
clear
D)
2.45 L done
clear
View Solution play_arrow
-
question_answer6)
A hydrocarbon contains 10.5 g carbon and 1g hydrogen. Its 2.4 g has 1 L volume as 1 atm and\[{{127}^{o}}C\]. Hydrocarbon is
A)
\[{{C}_{6}}{{H}_{7}}\] done
clear
B)
\[{{C}_{6}}{{H}_{6}}\] done
clear
C)
\[{{C}_{5}}{{H}_{6}}\] done
clear
D)
\[{{C}_{6}}{{H}_{6}}\] done
clear
View Solution play_arrow
-
question_answer7)
Nitric acid can be produced from \[N{{H}_{3}}\] in three step process |
I. \[4N{{H}_{3}}(g)+5{{O}_{2}}(g)\xrightarrow{{}}4NO(g)+6{{H}_{2}}O(g)\] |
II. \[2NO(g)+{{O}_{2}}(g)\xrightarrow{{}}2N{{O}_{2}}(g)\] |
III. \[3N{{O}_{2}}(g)+{{H}_{2}}O(l)\xrightarrow{{}}2HN{{O}_{3}}(aq)+NO(g)\] |
% yield of Ist, IInd and IIIrd are respectively 40%, 50% and 70% respectively, then what volume of\[N{{H}_{3}}(g)\] sit 1 atm and \[0{}^\circ C\] required to produce 1075 g of \[HN{{O}_{3}}\]? |
A)
3413 L done
clear
B)
3500 L done
clear
C)
6826 L done
clear
D)
1750 L done
clear
View Solution play_arrow
-
question_answer8)
It is known that atoms have proton, neutron, electron and nucleus. If the mass of neutron assumed to be half of its original value whereas that of proton is assumed to be twice the original value, then the atomic mass of \[_{6}{{C}^{14}}\] will be
A)
14.3% less than original value done
clear
B)
14.3% greater than original value done
clear
C)
28.6% less than original value done
clear
D)
28.6% greater than original value done
clear
View Solution play_arrow
-
question_answer9)
Arrange the following (I to IV) in the order of increasing masses. |
I. 0.5 mole of \[{{O}_{3}}\] |
II. \[3.01\times {{10}^{23}}\] molecules of \[{{O}_{2}}\] |
III. 5.6 L of \[C{{O}_{2}}\] at STP |
IV. 0.5 g atom of \[{{O}_{2}}\] |
A)
IV < III < II < I done
clear
B)
II < I < III < IV done
clear
C)
II = I < III < IV done
clear
D)
I < III < IV < II done
clear
View Solution play_arrow
-
question_answer10)
A 0.70 g sample consisting \[Ca{{C}_{2}}{{O}_{4}}\] and \[Mg{{C}_{2}}{{O}_{4}}\] is heated at \[300{}^\circ C,\] converting the two salts of \[CaC{{O}_{3}}\] and \[MgC{{O}_{3}}\]. The sample when weighs 0.47 g. If the sample had been heated to \[700{}^\circ C\] where the products are CaO and MgO. What would be the weight of mixture of oxides?
A)
0.36 g done
clear
B)
0.14 g done
clear
C)
0.28 g done
clear
D)
1.08 g done
clear
View Solution play_arrow
-
question_answer11)
23.2 g of an organic compound having molecular formula \[{{C}_{n}}{{H}_{2n+2}}\] is burnt in excess of \[{{O}_{2}}(g)\]initially taken in a 44.82 L steel vessel. Before reaction the gaseous mixture w at 273 K with pressure of 2 aim. After complete combustion and loss of considerable amount of heat the mixture of product and excess of had a temperature of 546 K and 4.6 atm pressure. The formula of compound is
A)
\[{{C}_{5}}{{H}_{12}}\] done
clear
B)
\[{{C}_{6}}{{H}_{10}}\] done
clear
C)
\[{{C}_{3}}{{H}_{8}}\] done
clear
D)
\[{{C}_{4}}{{H}_{10}}\] done
clear
View Solution play_arrow
-
question_answer12)
How many moles of electron weigh one kilogram?
A)
\[6.023\times {{10}^{23}}\] done
clear
B)
\[\frac{1}{9.108}\times {{10}^{31}}\] done
clear
C)
\[\frac{6.023}{9.108}\times {{10}^{54}}\] done
clear
D)
\[\frac{1}{9.108\times 6.023}\times 108\] done
clear
View Solution play_arrow
-
question_answer13)
The volume of concentrated sulphuric acid which is 98% by mass (density \[=1.84\,g\,c{{m}^{-3}}\]) required to prepare \[5\,d{{m}^{3}}\] of \[0.5\text{ }mol\text{ }d{{m}^{-3}}\] solution of sulphuric acid is
A)
272 mL done
clear
B)
68 mL done
clear
C)
136 mL done
clear
D)
204 mL done
clear
View Solution play_arrow
-
question_answer14)
2.76 g of silver carbonate on being strongly heated yields a residue weighing
A)
2.15 g done
clear
B)
2.48 g done
clear
C)
2.32 g done
clear
D)
2.64 g done
clear
View Solution play_arrow
-
question_answer15)
Two elements X and Y have atomic weights of 14 and 16. They form a series of compounds A, B, C, D and E in which the same amount of element X, Y is present in the ratio 1 : 2 : 3 : 4 : 5. If the compound A has 28 parts by weight of X and 16 parts by weight of Y, then the compound of C will have 28 parts weight of X and
A)
32 parts by weight of Y done
clear
B)
48 parts by weight of Y done
clear
C)
64 parts by weight of Y done
clear
D)
80 parts by weight of Y done
clear
View Solution play_arrow
-
question_answer16)
What weight of \[{{H}_{2}}{{C}_{2}}{{O}_{4}}\,\,2{{H}_{2}}O\,\,(\text{mol}\text{.}\,\text{wt}\text{.}\,=126)\] should be dissolved to prepare 250 ml of cent normal to be used as a reducing agent?
A)
0.63 gm done
clear
B)
0.1575 gm done
clear
C)
0.126 gm done
clear
D)
0.875 gm done
clear
View Solution play_arrow
-
question_answer17)
Apatite is a mineral that is found in tooth enamel. When fluoride toothpastes are used, this mineral is converted to fluoroapatite, which is more resistant to tooth decay. The formula of apatite is \[C{{a}_{5}}{{(P{{O}_{4}})}_{x}}F\]. What is the value of \[x\] if the compound contains 18.45% by weight of phosphorus? (Atomic weight of \[P=31,\,\,Ca=40,\]\[F=19\] and \[O=16\])
A)
2 done
clear
B)
4 done
clear
C)
5 done
clear
D)
3 done
clear
View Solution play_arrow
-
question_answer18)
Calculate the weight of lime (CaO) obtained by heating 200 kg of 95% pure lime stone \[(CaC{{O}_{3}}).\]
A)
104.4 kg done
clear
B)
105.4 kg done
clear
C)
212.8 kg done
clear
D)
106.4 kg done
clear
View Solution play_arrow
-
question_answer19)
The chloride of a metal has the formula \[MC{{l}_{4}}\]. The formula of its phosphate will be-
A)
\[{{M}_{2}}P{{O}_{4}}\] done
clear
B)
\[MP{{O}_{4}}\] done
clear
C)
\[{{M}_{3}}P{{O}_{4}}\] done
clear
D)
\[M{{(P{{O}_{4}})}_{2}}\] done
clear
View Solution play_arrow
-
question_answer20)
A silver coin weighing 11.34 g was dissolved in nitric acid. When sodium chloride was added to the solution all the silver (present as \[AgN{{O}_{3}}\]) was precipitated as silver chloride. The weight of the precipitated silver chloride was 14.35 g. Calculate the percentage of silver in the coin -
A)
4.8% done
clear
B)
95.2% done
clear
C)
90% done
clear
D)
80% done
clear
View Solution play_arrow
-
question_answer21)
A self-contained breathing apparatus used \[K{{O}_{2}}\] to convert \[C{{O}_{2}}\] and \[{{H}_{2}}O\] in exhaled air into oxygen and \[KHC{{O}_{3}}\] as shown in the equation \[K{{O}_{2}}+{{H}_{2}}O+C{{O}_{2}}\xrightarrow{\,}\,KHC{{O}_{3}}+{{O}_{2}}\]. |
How many molecules of \[{{O}_{2(g)}}\] will be produced from the 0.044 g of \[C{{O}_{2(g)}}\] that is exhaled in a typical breath? |
A)
\[6\times {{10}^{20}}\] done
clear
B)
\[4.5\times {{10}^{20}}\] done
clear
C)
\[2.25\times {{10}^{21}}\] done
clear
D)
\[4.5\times {{10}^{22}}\] done
clear
View Solution play_arrow
-
question_answer22)
The empirical formula of a compound composed of 38.4% potassium, 36.3% oxygen, 23.7% carbon and 1.66% hydrogen is determined to be
A)
\[~K{{C}_{2}}{{H}_{5}}{{O}_{4}}\] done
clear
B)
\[{{K}_{3}}{{C}_{6}}{{H}_{5}}{{O}_{7}}\] done
clear
C)
\[{{K}_{2}}CH{{O}_{3}}\] done
clear
D)
\[{{K}_{6}}{{C}_{4}}{{H}_{5}}{{O}_{7}}\] done
clear
View Solution play_arrow
-
question_answer23)
How many years it would take to spend Avogadro's number of rupees at the rate of 1 million rupees in one second?
A)
\[19.098\times {{10}^{19}}\] years done
clear
B)
\[19.098\] years done
clear
C)
\[19.098\times {{10}^{9}}\] years done
clear
D)
None of these done
clear
View Solution play_arrow
-
question_answer24)
15 grams of methyl alcohol is dissolved grams of water. What is the mass percent methyl alcohol in solution?
A)
30% done
clear
B)
50% done
clear
C)
70% done
clear
D)
75% done
clear
View Solution play_arrow
-
question_answer25)
Three isotopes of an element have mass numbers M, (M + 1) and (M + 2). The mean atomic mass is (M + 0.5). Then which of the following ratio maybe accepted for M, (M + 1), (M + 2) respectively
A)
1 : 1 : 1 done
clear
B)
4 : 1 : 1 done
clear
C)
3 : 2 : 1 done
clear
D)
2 : 1 : 1 done
clear
View Solution play_arrow
-
question_answer26)
A gaseous compound is composed of 85.7% by mass of carbon and 14.3% by mass of hydrogen. Its density is 22.8 g/L at 350 K and 1.0 atm pressure. Calculate the molecular formula of compound.
A)
\[{{C}_{5}}{{H}_{10}}\] done
clear
B)
\[{{C}_{6}}{{H}_{12}}\] done
clear
C)
\[{{C}_{4}}{{H}_{8}}\] done
clear
D)
\[{{C}_{8}}{{H}_{18}}\] done
clear
View Solution play_arrow
-
question_answer27)
If 3 moles of \[{{H}_{2}}\] and 1 mole of \[{{N}_{2}}\] are completely converted into \[N{{H}_{3}},\] the ratio of initial and final volume at the same temp. and pressure will be:
A)
1 done
clear
B)
3 done
clear
C)
2 done
clear
D)
4.20 done
clear
View Solution play_arrow
-
question_answer28)
1 mol of a gaseous aliphahatic compound\[{{C}_{n}}{{H}_{3n}}{{O}_{m}}\] is completely burnt in an excess of oxygen. The contraction in volume is (assume water get condensed out)
A)
\[\left( 1+\frac{1}{2}n-\frac{3}{4}m \right)\] done
clear
B)
\[\left( 1+\frac{3}{4}n-\frac{1}{4}m \right)\] done
clear
C)
\[\left( 1-\frac{1}{2}n-\frac{3}{4}m \right)\] done
clear
D)
\[\left( 1+\frac{3}{4}n-\frac{1}{2}m \right)\] done
clear
View Solution play_arrow
-
question_answer29)
X and Y are two elements which form \[{{X}_{2}}{{Y}_{3}}\] and \[{{X}_{3}}{{Y}_{4}}\]. If 0.20 mol of \[{{X}_{2}}{{Y}_{2}},\] weighs 32.0 g and 0.4 mol of \[{{X}_{3}}{{Y}_{4}}\] weighs 92.8 g, the atomic weights of X and Y are respectively
A)
16.0 and 56.0 done
clear
B)
8.0 and 28.0 done
clear
C)
56.0 and 16.0 done
clear
D)
28.0 and 8.0 done
clear
View Solution play_arrow
-
question_answer30)
How many H-atoms are present in 0.046 got ethanol?
A)
\[6\times {{10}^{20}}\] done
clear
B)
\[1.2\times {{10}^{21}}\] done
clear
C)
\[3\times {{10}^{21}}\] done
clear
D)
\[3.6\times {{10}^{21}}\] done
clear
View Solution play_arrow
-
question_answer31)
Chlorophyll, the green colouring matter of plants responsible for photosynthesis, contains 2.68% of magnesium by mass. Calculate the number of magnesium atoms in 2.00g of chlorophyll.
A)
\[1.345\times {{10}^{21}}\] done
clear
B)
\[1.345\times {{10}^{20}}\] done
clear
C)
\[13.45\times {{10}^{21}}\] done
clear
D)
\[1.345\times {{10}^{23}}\] done
clear
View Solution play_arrow
-
question_answer32)
Minimum amount of \[A{{g}_{2}}C{{O}_{3}}(s)\] required to produce sufficient oxygen for the complete combustion of C, H, which produces 11.2 ltr. of \[C{{O}_{2}}\] at S.T.P after combustion is: [Ag = 108] \[A{{g}_{2}}C{{O}_{3}}(s)\to 2Ag(s)+C{{O}_{2}}(g)+1/2{{O}_{2}}(g)\]\[{{C}_{2}}{{H}_{2}}+5/2{{O}_{2}}\to 2C{{O}_{2}}+{{H}_{2}}O\]
A)
276 g done
clear
B)
345 g done
clear
C)
690 g done
clear
D)
1380 g done
clear
View Solution play_arrow
-
question_answer33)
In the reaction \[4A+2B+3C\xrightarrow{{}}{{A}_{4}}{{B}_{2}}{{C}_{3}}\] what will be the number of moles of product formed. Starting from 2 moles of A, 1.2 moles of B & 1.44 moles of C:
A)
0.5 done
clear
B)
0. 6 done
clear
C)
0.48 done
clear
D)
4.64 done
clear
View Solution play_arrow
-
question_answer34)
About \[6\times {{10}^{-3}}\] mol \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}\] reacts completely with \[9\times {{10}^{-3}}\] mol \[{{X}^{n+}}\] to give \[X{{O}^{-}}_{3}\] and \[C{{r}^{3+}}\]. The value of \[n\] is:
A)
1 done
clear
B)
2 done
clear
C)
3 done
clear
D)
none of these done
clear
View Solution play_arrow
-
question_answer35)
About 0.5 g of hydrocarbon gave 0.9 g water on combustion. The percentage of carbon in hydrocarbon is:
A)
75.8 done
clear
B)
80.0 done
clear
C)
56.6 done
clear
D)
28.6 done
clear
View Solution play_arrow