A student dropped a few pieces of marble in dilute hydrochloric acid c

1.	A student dropped a few pieces of marble in dilute hydrochloric acid contained in a test tube. The evolved gas was passed through lime water. What change would beobserved in lime water ? Write balanced chemical equations for both the changes observed.(b) State the chemical property in each case on which the following uses of bakingsoda are based :1.as an antacid 2.as a constituent of baking powder.
Answer» $\rm{Answer:}$ (a) Marble used here is calcium carbonate - $\rm{CaCO_3}$ . When a few pieces of marble are dropped in HCl, $\rm{CO_2}$ GAS is evolved which when passed through lime water turns it milky due to the formation of insoluble calcium carbonate. Chemical EQUATIONS :- $\rm{CaCO_{3(s)}+HCl_{(aq)}\longrightarrow{}CaCl_{2(aq)}+H_2O_{(l)}+CO_{2(g)}}$ $\rm{Ca(OH)_{2(aq)}+CO_{2(g)}\longrightarrow{}CaCO_{3(s)}+H_2O_{(l)}}$ $\hrulefill$ (b) (i) Use of baking soda as an antacid : Baking soda is a mild non-corossive basic salt. Hence, it is basic in nature and neutralizes the excess acid formed in the stomach during INDIGESTION. $\hrulefill$ (ii) Baking powder contains baking soda and a mild edible acid. On heating, $\rm{NaHCO_3}$ decomposes to give $\rm{CO_2}$ gas and SODIUM carbonate. The bitter taste of $\rm{Na_2CO_3}$ is neutralized by tartaric or citric acid and $\rm{CO_2}$ gas produced causes bread and cake to rise.

A student dropped a few pieces of marble in dilute hydrochloric acid contained in a test tube. The evolved gas was passed through lime water. What change would beobserved in lime water ? Write balanced chemical equations for both the changes observed.(b) State the chemical property in each case on which the following uses of bakingsoda are based :1.as an antacid 2.as a constituent of baking powder.

Answer»

$\rm{Answer:}$

(a) Marble used here is calcium carbonate - $\rm{CaCO_3}$ . When a few pieces of marble are dropped in HCl, $\rm{CO_2}$ GAS is evolved which when passed through lime water turns it milky due to the formation of insoluble calcium carbonate.

Chemical EQUATIONS :-

$\rm{CaCO_{3(s)}+HCl_{(aq)}\longrightarrow{}CaCl_{2(aq)}+H_2O_{(l)}+CO_{2(g)}}$

$\rm{Ca(OH)_{2(aq)}+CO_{2(g)}\longrightarrow{}CaCO_{3(s)}+H_2O_{(l)}}$

$\hrulefill$

(b) (i) Use of baking soda as an antacid : Baking soda is a mild non-corossive basic salt. Hence, it is basic in nature and neutralizes the excess acid formed in the stomach during INDIGESTION.

$\hrulefill$

(ii) Baking powder contains baking soda and a mild edible acid. On heating, $\rm{NaHCO_3}$ decomposes to give $\rm{CO_2}$ gas and SODIUM carbonate. The bitter taste of $\rm{Na_2CO_3}$ is neutralized by tartaric or citric acid and $\rm{CO_2}$ gas produced causes bread and cake to rise.

$\rm{Answer:}$

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