Chemical Equations and Stoichiometry
Exam Duration: 45 Mins Total Questions : 30
In the following reaction,
\({ N }_{ 2 }(g)+3{ H }_{ 2 }(g)\rightarrow 2{ NH }_{ 3 }(g)\)
Calculate the moles of NH3 obtained when 2 moles of N2 react with 3 moles of H2 .
- (a)
2 mol
- (b)
4 mol
- (c)
1 mol
- (d)
6 mol
How many kilograms of CaCO3 will be required to produce 56 kg CaO, if the sample is 90% pure?
- (a)
90 kg
- (b)
110 kg
- (c)
100 kg
- (d)
111.11 kg
What is the mass per cent of carbon in carbon dioxide?
- (a)
0.034%
- (b)
27.27%
- (c)
3.4%
- (d)
28.7%
Calculate the mass per cent of different elements in sodium sulphate.
- (a)
Mass % of Na = 45.0; S = 32.37; O = 22.57
- (b)
Mass % of Na = 32.37; S = 22.57; O = 45.0
- (c)
Mass % of Na = 22.57; S = 45.0; O = 32.37
- (d)
Mass % of Na = 32.37; S =45.0; O = 22.57
What is the percentage of gold in 20 carat gold?
- (a)
80
- (b)
95
- (c)
38.56
- (d)
83.33
2 moles of BaCl2 react with 2 mole of Na3PO4 according to the reaction \(3BaC{ l }_{ 2 }+2N{ a }_{ 3 }{ PO }_{ 4 }\rightarrow { Ba }_{ 3 }{ \left( { PO }_{ 4 } \right) }_{ 2 }+6NaCl\) Calculate the maximum amount of Ba3(PO4)2 obtained.
- (a)
0.13 mol
- (b)
0.55 mol
- (c)
0.24 mol
- (d)
0.667 mol
If 0.56 g of a gas occupies 280 cm3 at STP, then what is the molecular mass of that gas?
- (a)
4.8
- (b)
44.8
- (c)
2
- (d)
22.4
How much of oxygen (in L) is required for the complete oxidation of 1.5 moles of sulphur into sulphur dioxide at STP?
- (a)
11.2
- (b)
22.4
- (c)
33.6
- (d)
44.8
If 500 mL of a 5 M solution is diluted to 1500 mL, what will be the molarity of the solution obtained?
- (a)
1.5 M
- (b)
1.66 M
- (c)
0.017 M
- (d)
1.59 M
What will be the molarity of a solution which contains 5.85 g NaCl(s) per 500 mL?
- (a)
4 mol L-1
- (b)
20 mol L-1
- (c)
0.2 mol L-1
- (d)
2 mol L-1
One mole of any substance contains 6.022X1023 molecules. Number of molecules of H2SO4 present in 100 mL of 0.02 MH2SO4 solution is
- (a)
12.044X1020 molecules
- (b)
6.022X1023 molecules
- (c)
1X1023 molecules
- (d)
12.044X1023 molecules
Calcium carbonate reacts with aqueous HCl to give CaCl2 and CO2 according to the following reaction \({ CaCO }_{ 3 }(s)+2HCl(aq)\rightarrow { CaCl }_{ 2 }(aq)+{ CO }_{ 2 }(g)+{ H }_{ 2 }O(l)\) What mass of CaCO3 is required to react completely with 25 mL of 0.75 M HCl?
- (a)
0.94 g
- (b)
0.24 g
- (c)
0.56 g
- (d)
0.49 g
\({ 2MnO }_{ 4 }^{ - }+{ 5C }_{ 2 }{ O }_{ 4 }^{ 2- }+{ 16H }^{ + }\rightarrow { 2Mn }^{ 2+ }+{ 10CO }_{ 2 }+{ 8H }_{ 2 }O\) Here, 20 mL of 0.1 M KMnO4 is equivalent to
- (a)
20 mL of 0.5 M H2C2O4
- (b)
50 mL of 0.1 M H2C2O4
- (c)
50 mL of 0.01 M H2C2O4
- (d)
20 mL of 0.1 M H2C2O4
Calculate the volume ( in mL) of 0.1 M KMnO4 solution required to completely oxidise 100 mL of 0.5 M ferrous sulphate solution in acidic medium?
- (a)
20
- (b)
50
- (c)
200
- (d)
100
How much of 0.1 N HCl is required to react with 1g of CaCO3 ? (Ca = 40, C = 14, O = 16)
- (a)
100 cm3
- (b)
150 cm3
- (c)
250 cm3
- (d)
200 cm3
Match the following and choose the correct option.
| Column I | Column II | ||
| A. | Molarity (M) | p. | Temperature |
| B. | Molarity (m) | q. | Dilution |
| C. | Mole fraction \((\chi )\) | r. | Volume |
| D. | Normality(N) |
- (a)
A B C D p,q,r q,r r q,p - (b)
A B C D p,q,r q q p,q,r - (c)
A B C D q,r p r p,r - (d)
A B C D p,q q q,r p,q
Calculate the mass per cent of calcium, phosphorus and oxygen in calcium phosphate, Ca3(PO4)2 .
- (a)
Ca:38.71%;P:20%;O:41.29%
- (b)
Ca:20%;P:38.7%;O:41.29%
- (c)
Ca:38.7%;P:41.29%O:20%
- (d)
Ca:20%;P:41.29%;O:38.71%
A sample of drinking water was found to be severely contaminated with CHCl3 supported to be carcinogenic in nature. The level of contamination was 15ppm. Which of the following is correct?
- (a)
Molarity of CHCl3 in water sample =1.26X10-4 M
- (b)
per cent by mass =1.5X10-2
- (c)
per cent by mass =1.5X10-6
- (d)
Molarity of CHCl3 in water sample = 1.26X10-3 M
If 4 g of NaOH dissolves in 36 g H2O. Calculate the molarity of the solution.
- (a)
1.5 M
- (b)
2.5 M
- (c)
2.0 M
- (d)
1.0 M
If 4g of NaOH dissolves in 36 g of H2O, calculate the mole fraction of each component in solution.
- (a)
\({ \chi }_{ { H }_{ 2 }o }=0.047:{ \chi }_{ NaOH }=0.95\)
- (b)
\({ \chi }_{ { H }_{ 2 }o }=0.25:{ \chi }_{ NaOH }=0.75\)
- (c)
\({ \chi }_{ { H }_{ 2 }o }=0.95:{ \chi }_{ NaOH }=0.047\)
- (d)
\({ \chi }_{ { H }_{ 2 }o }=0.75:{ \chi }_{ NaOH }=0.25\)
In the reaction, \(2A+4B\rightarrow 3C+4D;\) when 5 moles of A react with 6 moles of B, what is the limiting reagent?
- (a)
A
- (b)
B
- (c)
C
- (d)
D
In the reaction, \(2A+4B\rightarrow 3C+4D;\) when 5 moles of A react with 6 moles of B, then calculate amount of C formed.
- (a)
10
- (b)
4.5
- (c)
3
- (d)
4
35 mL of 0.1 M NaOH(aq) solution and 20 mL of 0.2 M NaOH (aq) solution is mixed and diluted to 100 mL. 40 mL of diluted solution reacted with 10% impure sample of oxalic acid (H2C2O4).What is the weight of impure sample?
- (a)
0.15 g
- (b)
0.135 g
- (c)
0.59 g
- (d)
None of the above
What is the concentration of sugar (C12H22O11) in mol L-1 if its 20 g are dissolved in enough water to make a final volume upto 2 L?
- (a)
0.0292 M
- (b)
0.0120 M
- (c)
0.0391 M
- (d)
0.0200 M
If the density of methanol is 0.793 kg L-1. What is volume needed for making 2.5 L of its 0.25 M solution?
- (a)
25.22 L
- (b)
2500 mL
- (c)
25.22 mL
- (d)
2500 L
Calculate the mass of sodium acetate required to make 500 mL of 0.375 molar aqueous solution. Molar mass of sodium acetate is 82.0245 mol-1 .
- (a)
14.21 g
- (b)
14.71 g
- (c)
15.00 g
- (d)
15.38 g
Experimentally, it was found that a metal oxide has formula Mo.98O. Metal M, present as M2+ and M3+ in its oxide. Fraction of the metal which exists as M3+ would be
- (a)
7.01%
- (b)
4.08%
- (c)
6.05%
- (d)
5.08%
The density (in g mL-1) of a 3.60 M sulphuric acid solution that is 29% H2SO4 (98 g mol-1) by mass will be
- (a)
1.64
- (b)
1.88
- (c)
1.22
- (d)
1.45
What volume of hydrogen gas, at 273 K and 1 atm pressure, will be consumed to obtain 21.6 g of elemental boron from the reduction of boron trichloride by hydrogen?
- (a)
89.6 L
- (b)
67.2 L
- (c)
44.8 L
- (d)
22.4 L
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