Stoichiometric Calculations

Q.

Balance the equation: $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2+{\mathrm{CO}}_2\to {\mathrm{CaCO}}_3+{\mathrm{H}}_2\mathrm{O}$

Q. Find the total number of electrons present in $1.6\text{g}$ of $C{H}_4$.

1. $6.023\times {10}^{23}$ electrons
2. $6.023\times {10}^{20}$ electrons
3. 10 electrons
4. 1 electron

Q. From $200\text{mg}$ of $C{O}_2$, ${10}^{21}$ molecules are removed. How many moles of $C{O}_2$ are left?

1. $2.88\times {10}^{-3}\text{mol}$
2. $7\times {10}^{-2}\text{mol}$
3. $2.88\times {10}^{-1}\text{mol}$
4. $2.8\text{mol}$

Q.

What happens when copper nitrate undergoes heating?

Q.

How many moles of ${\mathrm{Mg}}_3{\left({\mathrm{PO}}_4\right)}_2$, will contain $0.25$ mole of Oxygen atoms?

Q.

Calculate the number of aluminium ions present in 0.051 g of aluminium oxide.

Q. 1.00 g of oxygen combine with 0.126g of hydrogen to form h2o . 1.00g of nitrogen combine with 0.216g of hydrogen to form nh3. predict the weight of oxygen required to combine with 1.00 g of nitrogen to form an oxide.

Q.

One litre ${\mathrm{CO}}_2$ is passed through red hot coke. the volume becomes 1.4 liters at the same temperature and pressure. Write the composition of the product

Q. equivalent volume of Co2 in the following reaction will be n a 2 c o 3 + actual use NaCl + H2O + CO2.how mass of 1 equivalent of co2 = 22 g

Q. 4 g of hydrogen reacts with 20 gram of oxygen to form water .The mass of water formed is ? 1)24g. 2)36g. 3) 22.5 g. 4)40 g

Q. How many moles of iron can be made from the excess of $F{e}_2{O}_3$ using 16 mol of carbon monoxide in the following reaction?
$F{e}_2{O}_3+3CO\to 2Fe+3C{O}_2$

1. 11.22
2. 15.38
3. 10.67
4. 8.25

Q. alculate the mass of graphite that must be burnt to produce 13.2 g of CO2

Q. 1 mol of $KCl{O}_3$ is heated in the presence of $Mn{O}_2$. The produced oxygen is used to react with aluminium. Find the number of moles of aluminium oxide formed.

1. 2 mol
2. 1 mol
3. 4 mol
4. 3 mol

Q.

A certain weight of pure CaC$O_3$is made to react completely with 200 mL of an HCl solution to give 224 mL of C$O_2$gas at STP. The normality of the HCl is

1. 0.05 N

2. 0.1 N

3. 1.0 N

4. 0.2 N

Q. An element X reacts with oxygen to form a compound X2O3.if the atomic mass of X is 91.5 the equivalent mass of X is

Q.

Equal volumes of two gases A and B diffuse through a porous pot in 20s and 10s, respectively .If the molar mass of A be $80gmo{l}^{-1}$, Find the molar mass of B.

1. 

2. 

3. 

4. 

Q.

Calculate n-factor of $N{a}_{3}P{O}_4$ in the following reaction.

\(2 Na_3PO_4\) +\(3 BaCl_2\) $\to$ 6NaCl + $B{a}_3(P{O}_4{)}_2$

1. 2

2. 3

3. 4

4. 6

Q. 49, 0.5g of a metal on oxidation gave 0.79g of itsoxide. The equivalent mass of the metal is1) 102) 143) 204) 40

Q.

Solid ammonium dichromate (relative molecular mass 252) decomposes as under:

${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\to {\mathrm{N}}_2+{\mathrm{Cr}}_2{\mathrm{O}}_3+4{\mathrm{H}}_2\mathrm{O}$

If 63 g of ammonium dichromate decomposes, calculate the mass of chromium [III] oxide formed at the same time.

Q. 8. The mass of N2F4 produced by the reaction of 1 mole of Nh3 and 2.5 mole of F2 is 35.6 g. Hence, the percentage yield of the given reaction is?

Q.

1.12 ml of a gas is produced at STP by the action of 4.12 mg of alcohol, with methyl magnesium iodide. The molecular mass of alcohol is

1. 16
2. 41.2
3. 82.4
4. 156

Q. 4. A gaseous hydrocarbon required two and half times of its volume of O2 for complete combustion and produces double its volume of CO2. The molecular formula of the gas is?

Q. Silicon dioxide , made of elements silicon and oxygen contains 46.7% by mass of silicon.With what mass of oxygen will 10 g of silicon combine?

Q. Calculate the number of oxygen atoms required to combine with 7 g of $N_2$ to form $N_2{O}_3$ when $80\%$ of $N_2$ is converted to $N_2{O}_3$.

1. $7.2\times {10}^{23}$
2. $3.6\times {10}^{23}$
3. $1.8\times {10}^{21}$
4. $5.4\times {10}^{21}$

Q. A sample of hydrogen fluoride gas (only $HF$ molecules) is collected in a vessel and left for some time. Then, a constant molar mass of the sample is experimentally determined as $34gmo{l}^{-1}$. Assume that this abnormal molar mass is due to dimerization as well as trimerization of some $HF$ molecules (no molecules in any other polymeric forms) and the mole ratio of monomeric and trimeric forms of hydrogen fluoride molecules present is 4 : 1. What percentage of hydrogen fluoride molecules is dimerized?

1. $50$
2. $58.8$
3. $76.47$
4. $17.65$

Q. Calculate the amount of $H_2$ required to completely react with 112 litres of $C{l}_2$ at STP to produce $HCl$:

1. $8\text{g}$
2. $14\text{g}$
3. $10\text{g}$
4. None of these

Q. $NaBr$, used to produce $AgBr$ for use in photography can itself be prepared as follows:
$Fe+B{r}_2\to FeB{r}_2$
$FeB{r}_2+B{r}_2\to F{e}_{3}B{r}_8$ (not balanced)
$F{e}_{3}B{r}_8+N{a}_{2}C{O}_3\to NaBr+C{O}_2+F{e}_3{O}_4$ (not balanced)
How much $Fe$, in kg, is consumed to produce $4.12\times {10}^{3}kgNaBr$

Q. Simple ratio of masses of oxygen which combine with fixed mass of carbon in CO and CO2 is Options: 16 : 32 14 : 16 1 : 2 4 : 8

Q. If 1.11 g $M{g}_2{P}_2{O}_7$ is formed at the end of the reaction, then what weight of $Na{H}_{2}P{O}_4$ was present originally given that no other products contained phosphorus?
$\text{(Molar mass}M{g}_2{P}_2{O}_7=222gmo{l}^{-1},Na{H}_{2}P{O}_4=120gmo{l}^{-1})$
$Na{H}_{2}P{O}_4+M{g}^{2+}+N{H}_4^{+}\to Mg\left(N{H}_4\right)P{O}_4.6H_{2}O\to M{g}_2{P}_2{O}_7$

1. 2.1 g
2. 3.0 g
3. 5.0 g
4. 1.2 g

Q. what is the equivalent mass of AS2S3in the follwing reaction ( molar mass of AS2S3=M) AS2S3 + HNO3 + H+→ AS2O5 + HNO2 + So3 + H2