Tag: chemistry

Questions Related to chemistry

When baking soda reacts with vinegar, _________ is formed.

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. sodium carbonate

  2. sodium hydrogen carbonate

  3. sodium acetate

  4. none of above

Show answer
Correct Option: C
Explanation:

The reaction between baking soda (sodium bicarbonate) and vinegar (dilute acetic acid) generates carbon dioxide gas and sodium acetate.
$ NaHCO _3 + CH _3COOH \rightarrow  CH _3COONa + H _2O + CO _2 $

A constituent of gasoline is:

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. $NaHCO _3$

  2. $H _2SO _4$

  3. $CH _4$

  4. $Ca(OH) _2$

  5. $C _8H _{18}$

Show answer
Correct Option: E
Explanation:

A constituent of gasoline is octane $\displaystyle C _8H _{18}$.
Gasoline is also known as petrol. it contains a mixture of hydrocarbons.

How would you distinguish between baking powder over washing soda by heating?

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. Carbon dioxide is evolved in the reaction

  2. Carbon dioxide is not evolved in the reaction

  3. Hydrogen is evolved in the reaction

  4. They can be heated at high temperatures

Show answer
Correct Option: A
Explanation:

The production of carbon dioxide is main characteristic of baking soda that makes it suitable for baking.Baking soda gives carbon dioxide and water vapour on heating at even low temperature such as $1000^oC$. The gas so formed turns lime water milky, which confirms the presence of carbon dioxide gas. When Washing soda ($Na _2CO _3$) is heated it does not produce carbon dioxide even at high temperature, such as $200^0C$ or $300^oC$. However sodium carbonate gives sodium oxide and carbon dioxide when heated at about $1000^oC$.

The gas produced by heating of the samples can be checked by passing through lime water. If the lime water turns milky then the evolved gas is carbon dioxide and the heated substance is baking powder.

$2NaHCO _{3} \xrightarrow{Heat} Na _{2}CO _{3} + H _{2}O + CO _{2}$

$Na _{2}CO _{3}.10H _{2}O \xrightarrow{Heat}Na _{2}CO _{3} + 10H _{2}O$

Washing soda on strong heating gives sodium oxide and carbon dioxide.

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

$Na _2CO _3 (s) \rightarrow Na _2O (s) + CO _2 (g)$
From the above reaction, it shows that washing soda ($Na _2CO _3$) on heating gives sodium oxide and carbon dioxide.

Sodium hydrogen carbonate is used in fire extinguisher.

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

 Sodium hydrogen carbonate or sodium bicarbonate is used as a fire extinguisher. When heated to a high temperature, the chemical properties of this salt make it produce lots of carbon dioxide and remove oxygen. This reduces the amount of oxygen and puts the fire out. The reaction also produces a small quantity of water and sodium carbonate as by-products.
$2NaHCO _3 + H _2SO _4 \rightarrow Na _2SO _4 + 2H _2O + 2CO _2$

Solution of sodium hydrogen carbonate is alkaline in nature.

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Solution of sodium hydrogen carbonate is mildly alkaline due to the formation of carbonic acid and hydroxide ion:
$ HCO _3 + H _2O \rightarrow H2CO _3 + OH-$ 

Chemical formula of baking soda is:

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. $MgSO _4$

  2. $Na _2CO _3$

  3. $NaHCO _3 $

  4. $MgCO _3$

Show answer
Correct Option: C
Explanation:

Chemical formula of baking soda is $NaHCO _3$.

Which of the following give brisk effervescence with baking soda ?

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. methanoic acid

  2. propanoic acid

  3. ethanoic acid

  4. all of these

Show answer
Correct Option: D
Explanation:

The carboxylic acids react with baking soda to form sodium acetate, carbon dioxide and water. The general reaction can be written as:
$RCOOH + NaHCO _{3} \rightarrow CH _{3}COONa + CO _{2} + H _{2}O$
Thus the effervescence results from the release of carbon dioxide gas.

$NaHCO _{3}$ can be used on its own to make cakes or bread. Baking powder is more commonly used, and contains $NaHCO _{3}$, $Ca(H _{2}PO _{4}) _{2}$ and starch. An improved combination baking powder contains about 40% starch, 30% $NaHCO _{3}$ 20% $NaAl(SO _{4}) _{2}$ and 10% $Ca(H _{2}PO _{4}) _{2}.$ 

Answer the following questions based on above study.

Rise in bread and cakes is due to______ when it decomposes between $50^{o}C$ and $100^{o}C$. 

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. $CO _{2}$

  2. $H _{2}O$

  3. both (a) and (b)

  4. none of these

Show answer
Correct Option: A
Explanation:
This happens due to reaction: $NaHCO _3+ H^+ \rightarrow Na^+ + CO _2+ H _2O$ 

The carbon dioxide produced in these reactions causes the dough to rise (ferment or prove), and the alcohol produced mostly evaporates from the dough during the baking process.

$NaHCO _{3}$ can be used on its own to make cakes or bread. Baking powder is more commonly used, and contains $NaHCO _{3}$, $Ca(H _{2}PO _{4}) _{2}$ and starch. An improved combination baking powder contains about 40% starch, 30% $NaHCO _{3}$ 20% $NaAl(SO _{4}) _{2}$ and 10% $Ca(H _{2}PO _{4}) _{2}$

Answer the following questions based on above study.


In improved baking powder, $NaAl(SO _{4}) _{2}$ is used for :

chemistry substances in common use preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. makes the decomposition of $NaHCO _{3}$ faster

  2. slows the decomposition of $NaHCO _{3}$

  3. acts as filler

  4. makes the bread rise.

Show answer
Correct Option: B
Explanation:

Acid in a baking powder can be either fast-acting or slow-acting. $NaAl(SO _4) _2$ is a weak acid, it react with sodiumbicarbonate to produce $CO _2$ gas.

$NaAl(SO _4) _2 + 3NaHCO _3 \rightarrow AlOH _3 + 2Na _2SO _4 + 3CO _2$