Stoichiometric Calculations

Q. What do you mean by ppm?​

Q. What is the mass of $3.01\times {10}^{22}$ molecules of $N{H}_3$?

1. $6\text{g}$
2. $2\text{g}$
3. $0.85\text{g}$
4. $10\text{g}$

Q.

What volume of 0.10 M$H_{2}S{O}_4$ must be added to 50 ml of a 0.10 M NaOH solution to make a solution in which the molarity of the$H_{2}S{O}_4$ is 0.050 M?

1. 50 ml

2. 100 ml

3. 150 ml

4. 400 ml

Q.

$C{l}_2+2NaOH\to NaCl+\underset{–}{A}+H_{2}O$ to form. A is

(Cold & dilute)

1. 

2. 

3. 

4. None of these

Q. What is the valency of Magnesium in $M{g}_3{N}_2$?

Q. 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 $C_6{H}_{12}{O}_6$. 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 $1gc{m}^{-3}$.
Rreaction that takes place during photosynthesis is:
$6C{O}_2+6H_{2}O$ $⟶$ $C_6{H}_{12}{O}_6+6O_2$

Q.

100 ml mixture of Co and $C{O}_2$ is mixed with 30 ml of oxygen and sparked in a eudiometer tube. The residual gas after treatment with aqueous KOH has a volume of 10 ml which remains unchanged when treated with alkaline pyrogallol. If all the volumes are under the same conditions, point out the correct option(s).

1. The volume of CO that reacts, is 60 ml

2. The volume of CO that remains unreacted, is 10 ml

3. The volume of $O_2$ that remains unreacted, is 10 ml

4. The volume of $C{O}_2$ that gets absorbed by aqueous KOH, is 90 ml

Q.

Correct the following statements-
Aqua regia contains one part by volume of nitric acid and three parts by volume of hydrochloric acid.

Q.

Aniline is diazotized and the diazonium salt hydrolysed to yield phenol which is brominated to produce $C_6{H}_2\left(B{r}_3\right)OH.$ Calculate the mass of the final product obtained from 9.3 g of aniline if the yield in the two steps is 45% and 70% (Atomic mass of Br = 80) ?

1. 1.04 g

2. 14.89 g

3. 23.17 g

4. 10.43 g

Q.

In an experiment, 100 ml of ozonised oxygen was reduced to 60 ml when treated with turpentine. What would be the increase in volume if the original sample was heated until no further change occured ?(All volumes were measured under identical conditions). ?

1. 40 ml

2. 10 ml

3. 20 ml

4. 30 ml

Q.

Two elements whose symbols are derived from the first and third letter of the name are _____ and ______

Q. For the reaction: $7A+13B+15C\to 17P$
If 15 moles of A, 26 moles of B and 30.5 moles of C are taken initially, then the limiting reagent is:

1. A
2. B
3. None of these
4. C

Q.

NH₄Cl+NaOH=

Q. Explain with examples what is meant by a 'mole' of a substance.

Q.

Oxygen oxidises ethyne to carbon dioxide and water as shown by the equation :

$2{\mathrm{C}}_2{\mathrm{H}}_2+5{\mathrm{O}}_2\to 4{\mathrm{CO}}_2+2{\mathrm{H}}_2\mathrm{O}$

What volume of ethyne gas at STP is required to produce 8.4cm³ of carbon dioxide at STP? (H= 1, C=12, O= 16)

Q. If 0.2 mol of sodium chloride is required how many grams of sodium chloride should be taken?

Q.

Sulfuryl chloride $\left(S{O}_{2}C{l}_2\right)$ reacts with water to give a mixture of $H_{2}S{O}_4$ and HCl. How many moles of baryta would be required to neutralize the solution formed by adding 1 mole of $S{O}_{2}C{l}_2$ to excess of water ?

1. 4

2. 3

3. 2

4. 1

Q. What volume of oxygen, measured at standard conditions, can be produced by heating 10 g of potassium chlorate $KCl{O}_3$?

1. $7.24L$
2. $5.47L$
3. $4.27L$
4. $2.74L$

Q. The percentage by mole of ${NO}_2\left(g\right)$ in a mixture of ${NO}_2\left(g\right)$ and $NO\left(g\right)$ having average molecular mass 34 is :

1. 25%
2. 20%
3. 40%
4. 75%

Q.

100 ml of 1M NaOH and 100ml of $Xg{L}^{-1}{H}_{2}S{O}_4$, both being at the same temperature, are mixed. The highest rise in temperature would occur when X is ?

1. 0.49 g

2. 4.9 g

3. 49g

4. 60g

Q. The total vapour pressure of an ideal binary solution is given by

P = (100X_A + 250X_B) Torr

where X_A and X_B are mole fraction of components A and B in solution phase. Choose the correct statement(s) from the following.

एक आदर्श द्विअंगी विलयन का कुल वाष्प दाब निम्न प्रकार दिया जाता है।

P = (100X_A + 250X_B) टोर

जहाँ X_A तथा X_B विलयन प्रावस्था में घटक A तथा B के मोल प्रभाज हैं। निम्नलिखित में से सही कथन/कथनों का चयन कीजिए।

1. Vapour pressure of solution is more than the vapour pressure of pure component - A
   
   विलयन का वाष्प दाब शुद्ध घटक - A के वाष्प दाब से अधिक है
   
2. Vapour pressure of solution is less than the vapour pressure of pure component - B
   
   विलयन का वाष्प दाब शुद्ध घटक - B के वाष्प दाब से कम है
   
3. Vapour pressure of pure component-A is 100 Torr
   
   शुद्ध घटक-A का वाष्प दाब 100 टोर है
   
4. Vapour pressure of pure component-B is 250 Torr
   
   शुद्ध घटक-B का वाष्प दाब 250 टोर है
   

Q. Is density of ice maximum at 4 degree Celsius

Q.

Which of the following statements are correct for a solution of $H_2{O}_2$ having a strength of 17g/litre ?

1. The volume strength $H_2{O}_2$ solution is 5.6 at 1 atmosphere pressure and 273 K temperature

2. The molarity of given $H_2{O}_2$ solution is 0.5 M

3. 1 ml of the given $H_2{O}_2$ solution will give out 2.8 ml of $O_2$ at 2 atmosphere pressure and 273 K temperature

4. The normality of given $H_2{O}_2$ solution is 2N.

Q. Suppose the elements X and Y combine to form two compounds $X{Y}_2$ and $X_3{Y}_2$. When 0.1 mole of $X{Y}_2$ weighs 10 g and 0.05 mole of $X_3{Y}_2$ weighs 9 g, the atomic weights of X and Y are :

1. 20, 30
2. 60, 40
3. 40, 30
4. 30, 20

Q. Chlorine has two naturally occurring isotopes, ${}^{35}Cl$ and ${}^{37}Cl$. If the atomic mass of Cl is $35.45$, the ratio of natural abundance of ${}^{35}Cl$ and ${}^{37}Cl$ is closest to:

1. $3.5:1$
2. $3:1$
3. $2.5:1$
4. $4:1$

Q.

A sample of hard water from some source was found to release carbon dioxide gas when boiled. It is possible to titrate the sample of water from the same source with ?

1. dil HCl

2. dil NaOH

3. Neither (a) nor (b)

4. A good reducing agent such as sodium metal

Q. A compound has the following % composition. $Zn=$ 22.65 %; $S=$ 11.15 %; $O=$ 61.32 % and $H=$ 4.88%. Its relative molecular mass is 287 g. Calculate its molecular formula assuming that all the hydrogen in the compound is present in combination with oxygen as a water of crystallization.
[$Zn=65,S=32,O=16,H=1$]

1. $ZnS{O}_4.7H_{2}O$
2. $ZnS{O}_4$
3. $ZnS{O}_4.6H_{2}O$
4. $ZnS{O}_4.5H_{2}O$

Q. $AgN{O}_3+NaCl\to AgCl+NaN{O}_3$
Which of the following statements for the above reaction is true

1. 1 mol of reacts with 1mol of
2. 1g of reacts with 1g of
3. 1ml of reacts with 1ml of
4. All of the above

Q.

12 g of Mg (at. mass 24) will react completely with acid to give

1. $\frac{1}{2}$ mole of $H_2$
2. $\frac{2}{3}$ mole of $O_2$
3. Both $\frac{1}{2}$ mol of $H_2$ and $\frac{1}{2}$ mol of $O_2$
4. One mole of $H_2$