Chemistry, 22.12.2019 21:31 stella013108

Solution x mixed with magnesium chloride solution to form a white precipitate. the white precipitate obtained and reacted with dil hcl to give colourless gas bubbles turn lime water milky
what is solution x?

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Answer from: lacourboud20005

Solution X might be a solution of carbonate ions $\text{CO}_3^{2-}\;(aq)$ .

The question doesn't tell much about the positive ion in solution X. The ion itself shall not react with carbonate ions $\text{CO}_3^{2-}\;(aq)$ to form a precipitate. For that, cations from group 1 metals will work. For example, X can be a solution of sodium carbonate, which contain a large number of sodium ions $\text{Na}^{+}\;(aq)$ .

Explanation:

Start with the first observation:

"Solution X mixed with magnesium chloride solution to form a white precipitate."

A solution of magnesium chloride $\text{MgCl}_2\;(aq)$ contains both

$\text{Mg}^{2+}\;(aq)$ ions and $\text{Cl}^{-}\;(aq)$ ions.

Both may react to form a white precipitate.

$\text{Mg}^{2+}\;(aq)$ ions:

$\text{Mg}^{2+}\;(aq)$ might react with hydroxide ions $\text{OH}^{-}\;(aq)$ to form the white-colored, weakly-soluble base magnesium hydroxide $\text{Mg}(\text{OH})_2\;(s)$ . $\text{Mg}^{2+}\;(aq)$ might also react with carbonate ions $\text{CO}_3^{2-}$ to form the white-colored, insoluble salt magnesium carbonate, $\text{MgCO}_3\;(s)$ .

$\text{Cl}^{-}\;(aq)$ ions:

$\text{Cl}^{-}\;(aq)$ ions might react with silver ions $\text{Ag}^{+}\;(aq)$ to form the white-yellowish insoluble salt silver chloride $\text{AgCl}\;(s)$ .

Second observation:

"The white precipitate obtained and reacted with [dilute] HCl to give [colorless] gas bubbles."

Indeed $\text{Mg}(\text{OH})_2\;(s)$ will react with dilute HCl, but no gas will be formed: $\text{Mg}(\text{OH})_2\;(s) +2\;\text{HCl}\;(aq)\to\text{MgCl}_2\;(aq) + 2\;\text{H}_2\text{O}\;(l)$ . $\text{MgCO}_3\;(s)$ reacts with dilute HCl to produce the colorless gas carbon dioxide $\text{CO}_2\;(g)$ : $\text{MgCO}_3\;(s) + 2\;\text{HCl}\;(aq) \to\text{MgCl}_2\;(aq)+\text{H}_2\text{O}\;(l) +\text{CO}_2\;(g)$ .Silver chloride $\text{AgCl}\;(s)$ does not react with dilute HCl.

The carbon dioxide gas from the reaction between $\text{MgCO}_3\;(s)$ and dilute HCl reacts with lime water (saturated calcium hydroxide $\text{Ca}(\text{OH})_2\;(aq)$ solution in water) to form the white-colored, insoluble salt calcium carbonate $\text{CaCO}_3\;(s)$ . The $\text{CaCO}_3\;(s)$ precipitate will turn the lime water milky.

In summary,

$\rm \underbrace{\text{Na}_2\text{CO}_3\;(\rm aq)}_{\text{White Precipitate}} + \text{MgCl}_2 \;(aq) \to 2\;\text{NaCl}\;(aq) + \underbrace{\text{MgCO}_3\;(\rm s)}_{\text{White Precipitate}$ .

$\rm \underbrace{\text{MgCO}_3\;(\rm s)}_{\text{From Solution X}} + \text{HCl} \;(aq) \to \text{MgCl}_2\;(aq) + \rm H_2O\;( aq) + \underbrace{{\rm CO_2}\;(g)}_{\rm Colorless\;Gas}$ .

$\rm Ca(OH)_2\;(aq)+CO_2\;(g)\to \underbrace{\rm CaCO_3\;(s)}_{\begin{aligned}&\small\text{Turns Lime}&\\[-0.5em]&\small\text{Water Milky}&\end{aligned}} + H_2O\;(l)$ .

Answer from: Quest

- decrease the number of plants and animals living in the water.

Answer from: Quest

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .