Molarity

Q. Find the molality of 15% (w/w) solution of $H_{2}S{O}_4$.

1. 1.09 m
2. 2.05 m
3. 1.64 m
4. 1.80 m

Q.

What is a decimolar solution?

Q. $100\text{mL}$ of an $H_{2}S{O}_4$ solution that has a molarity of $1\text{M}$ and density of $1.50\text{g/mL}$ is mixed with $400\text{mL}$ of water. If the final density of the resulting solution is $1.25\text{g/mL}$, the final molarity of the $H_{2}S{O}_4$ solution is:

1. $4.40\text{M}$
2. $0.145\text{M}$
3. $0.520\text{M}$
4. $0.227\text{M}$

Q. What is the molarity of an $NaOH$ solution if 250 mL contains 1 mg of $NaOH$?

1. ${10}^{-1}M$
2. ${10}^{-2}M$
3. ${10}^{-4}M$
4. ${10}^{-3}M$

Q. With increase of temperature, which of these changes?

1. Molality
2. Weight fraction of solute
3. Mole fraction
4. Molarity

Q. 8 g of NaOH is dissolved in 18 g of $H_{2}O$. Find the mole fraction and molality (mol $k{g}^{-1})$ of NaOH in the resultant solution.

1. 0.2, 11.11
2. 0.167, 22.2
3. 0.2, 22.2
4. 0.167, 11.11

Q. Calculate the resultant molarity on mixing 2500 mL of a 2.5 M $HN{O}_3$ solution and 157.5 g of $HN{O}_3$.

1. 3.5 M
2. 2.8 M
3. 1.5 M
4. 4.7 M

Q. What is the concentration of nitrate ions if equal volumes of 0.1 M $AgN{O}_3$ and 0.1 M NaCl are mixed together

1. 0.1 M
2. 0.2 M
3. 0.05 M
4. 0.25 M

Q. What is molality of 30% (w/w) $H_2{O}_2$ aqueous solution?

1. 8.82 m
2. 10.67 m
3. 12.60 m
4. 15.60 m

Q. 100 mL of a 1 M $H_{2}S{O}_4$ solution is diluted with 400 mL of water. Calculate the molarity of the resultant $H_{2}S{O}_4$ solution.

1. 0.50 M
2. 0.10 M
3. 0.01 M
4. 0.20 M

Q. How many $mL$ of $H_{2}S{O}_4$ of density $1.8gm{L}^{-1}$ containing $92.5\%$ by volume of $H_{2}S{O}_4$ should be added to $1L$ of $40\%$ solution of $H_{2}S{O}_4$ (density $1.3gm{L}^{-1}$) in order to prepare $50\%$ solution of $H_{2}S{O}_4$ (density $1.4gm{L}^{-1}$)?

1. 188
2. 186
3. 210
4. 212

Q. 100 mL of a 0.1 M HCl solution, 200 mL of a 0.2 M HCl solution, 300 mL of a 0.3 M HCl solution, 400 mL of a 0.4 M HCl solution and 500 mL of a 0.5 M HCl solution are mixed. 200 mL of this solution is diluted with 300 mL of water. What is the molarity of HCl in the resultant solution?

1. 0.147 M
2. 0.375 M
3. 0.765 M
4. 0.625 M

Q.

What is the unit of molality?

Q. 100 mL of a 0.1 M HCl solution, 200 mL of a 0.2 M $HN{O}_3$ solution and 200 mL of a 0.5 M NaOH solution were mixed. The resultant solution will be

1. Acidic
2. Basic
3. Neutral
4. Can't say

Q. $100\text{mL}$ of $1\text{M}$ $NaCl$ solution is mixed with $100\text{mL}$ of $3\text{M}$ $HCl$ solution and $200\text{mL}$ of $1\text{M}$ $CaC{l}_2$ solution. Which of the following statements is true?

1. The ratio of concentrations of cations to anions is $\frac{3}{4}$
2. The ratio of cations to anions is 2
3. $\text{Molarity of}C{l}^{-}=\frac{1}{2}M$
4. $\text{Molarity of}C{l}^{-}=\frac{3}{2}M$

Q. Calculate the molarity of the resultant solution in each of the following cases:
i. 200 mL of 1 M HCl + 300 mL water
ii. 200 mL of 1 M HCl + 100 mL of 0.5 M HCl

1. $0.4M,\frac{5}{6}M$
2. 0.4 M, 0.5 M
3. $0.2M,\frac{5}{6}M$
4. 0.5 M, 0.5 M

Q. What is the molarity of $KN{O}_3$ in a solution prepared by dissolving 3.75 g of $KN{O}_3$ in water to make a 375 mL solution?
(Molar mass of $KN{O}_3$ = 101 g/mol)

1. 0.2 M
2. 0.5 M
3. 0.1 M
4. 0.3 M

Q. If 200 mL of a standard 0.15 M NaOH solution is required to neutralize 30 ml of $H_{2}S{O}_4$, what is the molarity of acid?

1. 2.0 M
2. 0.5 M
3. 1.5 M
4. 1.0 M

Q. 150 mL of a $H_2{O}_2$ sample was divided into two parts. The first part was treated with $KI$ and the formed $KOH$ required 200 mL of $\frac{M}{2}$ $H_{2}S{O}_4$ for neutralization. The other part was treated with $KMn{O}_4$, yielding 6.72 L of $O_2$ at 1 atm and 273 K. Using the given % yields find the molarity of $H_2{O}_2$.
$H_2{O}_2+2KI⟶I_2+2KOH(Yield=40\%)$
$H_2{O}_2+2KMn{O}_4+3H_{2}S{O}_4⟶K_{2}S{O}_4+2MnS{O}_4+3O_2+4H_{2}O(Yield=50\%)$

1. 1.4 M
2. 3.0 M
3. 1.5 M
4. 2.4 M

Q. 50 mL of 0.05 M $BaC{l}_2$ (aq) solution and 100 mL of 0.1 M of KCl (aq) solutions are mixed. Calculate the molarity of $C{l}^{-}$ ions in the resulting solution.

1. 0.33 M
2. 0.10 M
3. 0.66 M
4. 1.33 M

Q. What is the molarity of a 49% $H_{3}P{O}_4$ solution by mass?
(Density of the solution = 1.33 g/mL)

1. 0.66 M
2. 4.9 M
3. 6.65 M
4. 5 M

Q. 250 mL of a sodium carbonate solution contains 2.65 g of $N{a}_{2}C{O}_3.$ If this solution is diluted to 1 L, what is the molarity of the resultant solution?

1. 0.025 M
2. 0.250 M
3. 0.055 M
4. 0.067 M

Q.

Which among the following contain 43.4% of sodium?

1. sodium bicarbonate

2. sodium nitrate

3. sodium carbonate

4. sodium chloride

Q. 2 L of 2.5 M $H_{2}S{O}_4$ solution is diluted to 15 L. Calculate the molarity of the resulting solution.

1. 1.25 M
2. 0.15 M
3. 0.78 M
4. 0.33 M

Q. 1 M HCl and 2 M HCl are mixed in volume ratio of 4:1. The resulting HCl solution is diluted to double its original volume. What is the final molarity of HCl solution?

1. 0.75 M
2. 1.2 M
3. 0.6 M
4. 1.5 M

Q. Equal volumes of $0.1\text{M}AgN{O}_3$ and $0.2\text{M}NaCl$ are mixed. The concentration of $N{O}_3^{-}$ ions in the mixture will be:

1. $0.1\text{M}$
2. $0.05\text{M}$
3. $0.20\text{M}$
4. $0.15\text{M}$

Q. Calculate the volume of concentrated sulphuric acid (molarity = 18 M) required to prepare 250 mL of 2 M acid solution.

1. 27.8 mL
2. 15.4 mL
3. 20.5 mL
4. 23.6 mL

Q. Which of the following will give 60 ml of 0.4 M NaOH solution?

1. 20 ml 1.2 M NaOH solution is mixed in 40 ml water
2. 20 ml of 1 M NaOH solution is mixed with 40 ml of 0.1 M NaOH solution
3. 0.4 g of NaOH and 20 ml of 0.7 M solution of NaOH are added to 40 ml water
4. 0.48 g of NaOH is added to 60 ml of 0.2 M NaOH solution

Q. How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2.0 M $HN{O}_3$?
(The concentrated acid is 70 % $HN{O}_3$ by weight)

1. 90 g
2. 45 g
3. 70 g
4. 54 g

Q. A solution of $H_{3}P{O}_4$ is 98% by mass. Calculate the molarity and normality if the density of the solution is 1.8 g/mL.

1. 18 M, 18 N
2. 18 M, 54 N
3. 6 M, 18 N
4. 54 M, 18 N