Bases

Q.

What is the difference between acids and bases?

Q.

Which of the following is not a property of bases?

1. Bases are bitter in taste

2. Bases do not change the colour of red litmus.

3. Bases turn red litmus blue​

4. Bases are soapy to touch

Q.

Identify the only base which does not have a metal in its molecule.

1. $Mg(OH{)}_2$ (Magnesium Hydroxide).

2. $Ca(OH{)}_2$ (Calcium Hydroxide).

3. $N{H}_{4}OH$ (Ammonium hydroxide).

4. $NaOH$ (Sodium Hydroxide).

Q. Which of the following base do not contain metallic atoms?

1. $NaOH$
2. $N{H}_{4}OH$
3. $Ca(OH{)}_2$
4. $Al(OH{)}_3$

Q.

We are using a large number of substances such as lemon, orange juice, baking soda and vinegar in our daily life. Which of the following substance has a bitter taste?

1. Lemon

2. Vinegar

3. Orange juice

4. Baking soda

Q. Is copper carbonate a base

Q. Which of the following bases is a weak base?

1. Sodium hydroxide.
2. Potassium hydroxide.
3. Lithium hydroxide.
4. Calcium hydroxide.

Q.

What happens when [5 MARKS]

a) A red litmus paper is dipped in a solution of calcium hydroxide.

b) A red litmus paper is dipped in a solution of sodium chloride.

c) A blue litmus paper is dipped in lemon juice.

d) A red litmus paper is dipped in distilled water.

e) A solution of sodium hydroxide is added to turmeric.

Q. State differences between acids and bases. [3 MARKS]

Q.

What happens when?

a) A solution of calcium hydroxide is added to red litmus paper

b) A solution of sodium chloride is added to red litmus paper

c) A solution of lemon juice is added to blue litmus paper

d) A solution of distilled water is added to red litmus paper

e) A solution of sodium hydroxide is added to turmeric [5 MARKS]

Q. What is alkali?

Q.

Milk of magnesia is ___ in nature.

Q. Question 1
State three differences between acids and bases.

Q.

You find a substance that is bitter in taste. When you rubbed its solution on your fingers, it felt soapy. What is this substance? Give an example of a substance of similar nature. [2 MARKS]

Q. What is base?

Q.

When bitten by an ant, the sting causes irritation due to the presence of

1. a base in the sting.

2. formic acid in the sting.

3. poisonous chemicals.

4. Both (1) and (2)

Q.

Among the given four bases, which one is considered as the weakest base?

1. Sodium hydroxide

2. Potassium hydroxide.

3. Lithium hydroxide.

4. Calcium hydroxide.

Q.

Which of the following option correctly represents the pH value of an acid and a base?

1. Acid - 7 and base - 5

2. Acid - 3 and base - 7

3. Acid - 8 and base - 5

4. Acid - 3 and base - 9

Q. Limewater is a solution of _______ in water.

1. sodium chloride
2. calcium chloride
3. sodium hydroxide
4. calcium hydroxide

Q.

The pH value of a neutral solution is 7.

(i) What is the pH value of an alkaline solution? Less than 7 or greater than 7.

(ii) What is the pH value of an acidic solution? Less than or greater than 7.

Q.

Pick the odd one out.

1. Orange juice

2. Ant bite

3. Vinegar

4. Calamine

Q.

Write some of the most significant application of acids and bases.

Q.

Question 2
Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?

Q.

Is there any acid or base found on any celestial body except earth?

Q. Which of the following pair of substances contains only base?

1. Vinegar and lemon
2. Limewater and curd
3. Soap and toothpaste
4. Apple and tamarind

Q.

Look at the table given below and fill in the blanks with correct word(s). [3 MARKS]

$\begin{array}{ccc}Properties& Acid& Base\\ RedLitmus& \left(i\right)\text{\_\_\_\_\_}& Turnstoblue\\ Taste& Sour& \left(ii\right)\text{\_\_\_\_\_}\\ Extractofredcabbage& \left(iii\right)\text{\_\_\_\_\_}& Turnstogreenishcolor\end{array}$

Q.

What would happen when a red litmus paper is treated with a solution containing NaOH? [2 MARKS]

Q. Preeti has collected some items from her kitchen:​
i. Amla​
ii. Baking soda​
iii. Tamarind​
iv. Soap​
v. Limewater​
vi. Common salt​
vii. Sugar​
She classified them as acidic, basic and neutral substances. Which of the following classification is correct?​

Q. 0.5g of Ba-hydroxide , 0.01 mol Ba-hydroxide and 0.01eq Ba-hydroxide were together diluted to one litre. Calculate the normality of the basic solution.

Q.

Which of the following is not a property of base?

1. Bases are bitter in taste

2. Bases do not change the colour of red litmus.

3. Bases turn red litmus blue​

4. Bases are soapy to touch