Grade 10 : Science - 2. Acids/Bases (Set 4) | Concept of Maths

Question 1

A student performs a titration by adding $0.1M\ NaOH$ to $25\ mL$ of $0.1M\ HCl$. Which of the following graphs correctly describes the change in pH as the volume of base increases?

[Visual Description]: Graph A starts at pH 7 and rises. Graph B starts at pH 13 and drops. Graph C starts at pH 1, stays low, then rises sharply at 25 mL to cross pH 7. Graph D is a straight horizontal line.

Accepted Answer

C) Graph C

Answer

A) Graph A

Answer

B) Graph B

Answer

D) Graph D

Question 2

In an experiment, Zinc granules are reacted with dilute $H_2SO_4$. The evolved gas is passed through a soap solution. When a burning candle is brought near the bubbles, they burst with a "pop" sound. What is the pH range of the resulting salt solution in the flask?

Accepted Answer

B) $pH \approx 7$

Answer

A) $pH < 7$

Answer

C) $pH > 7$

Answer

D) $pH = 0$

Question 3

Consider a conductivity setup with two electrodes dipped in a solution. A bulb in the circuit glows brightly for Solution A but very dimly for Solution B. If both solutions have a concentration of $0.1M$, which pair is most likely?

Accepted Answer

A) HCl, B: $CH_3COOH$

Answer

A) $CH_3COOH$, B: NaOH

Answer

A) Glucose, B: HCl

Answer

A) $NH_4OH$, B: $H_2SO_4$

Question 4

A beaker contains $10\ mL$ of an aqueous solution with $pH = 2$. If $90\ mL$ of distilled water is added to this beaker, what will be the approximate new pH of the solution?

Accepted Answer

D) $pH = 3$

Answer

A) $pH = 1$

Answer

B) $pH = 12$

Answer

C) $pH = 2.1$

Question 5

In the Chlor-alkali process, three products are formed. A student labels the gas collected at the Anode as 'X'. If 'X' is passed over dry slaked lime, it produces a substance used for bleaching. Identify 'X'.

Accepted Answer

B) $Cl_2$ gas

Answer

A) $H_2$ gas

Answer

C) $O_2$ gas

Answer

D) $CO_2$ gas

Question 6

A mystery substance 'Z' turns Universal Indicator paper purple. When 'Z' reacts with Ammonium Chloride ($NH_4Cl$) and is heated, a gas with a pungent smell is evolved. What is substance 'Z'?

Accepted Answer

C) NaOH

Answer

A) $CH_3COOH$

Answer

B) $Distilled\ Water$

Answer

D) $Lemon\ Juice$

Question 7

A student observes a reaction where a gas produced by the action of HCl on $CaCO_3$ is passed through a clear liquid, turning it milky. If the gas is passed in excess, the milkiness disappears. This disappearance is due to the formation of:

Accepted Answer

A) $Ca(HCO_3)_2$

Answer

B) CaO

Answer

C) $CaCl_2$

Answer

D) $Ca(OH)_2$

Question 8

A heating curve for $CuSO_4 \cdot 5H_2O$ shows a color change from Blue to White at $100^{\circ}C$. If the white powder is cooled and a few drops of water are added, what visual change occurs?

Accepted Answer

B) It turns blue again.

Answer

A) It remains white and dissolves.

Answer

C) It turns green.

Answer

D) It starts effervescing.

Question 9

Solution P has a pH of 4, Solution Q has a pH of 7, and Solution R has a pH of 10. If a drop of Methyl Orange is added to each, what will be the colors observed?

Accepted Answer

D) P: Red/Pink, Q: Yellow, R: Yellow

Answer

A) P: Yellow, Q: Orange, R: Red

Answer

B) P: Red, Q: Red, R: Yellow

Answer

C) P: Yellow, Q: Yellow, R: Yellow

Question 10

An antacid tablet containing $Mg(OH)_2$ is titrated with gastric juice (HCl). Which chemical equation correctly represents the neutralization reaction occurring in the stomach?

Accepted Answer

C) $Mg(OH)_2 + 2HCl \rightarrow MgCl_2 + 2H_2O$

Answer

A) $Mg(OH)_2 + HCl \rightarrow MgCl + H_2O$

Answer

B) $Mg(OH)_2 + 2HCl \rightarrow MgCl_2 + H_2$

Answer

D) $Mg + 2HCl \rightarrow MgCl_2 + H_2$