Question

multiple choice 2 points which substance(s) in the original sample are soluble in water? sio₂ nacl caco₃ sio₂ and nacl caco₃ and nacl caco₃ and sio₂ sio₂ and nacl and caco₃ multiple choice 2 points which substance(s) in the original sample react with hcl? sio₂ nacl caco₃ sio₂ and nacl caco₃ and nacl

Explanation:

1. For the solubility question:

• $SiO_2$ (silicon - dioxide) is a covalent network solid and is insoluble in water.
• $NaCl$ (sodium chloride) is an ionic compound and is highly soluble in water due to ion - dipole interactions.
• $CaCO_3$ (calcium carbonate) is insoluble in water as the lattice energy is high and not easily overcome by the hydration energy.

1. For the reaction with $HCl$ question:

• $SiO_2$ does not react with $HCl$ under normal conditions.
• $NaCl$ is a salt and does not react with $HCl$ as it already contains chloride ions.
• $CaCO_3$ reacts with $HCl$ according to the equation $CaCO_3 + 2HCl=CaCl_2 + H_2O+CO_2\uparrow$.

Answer:

1. B. $NaCl$
2. C. $CaCO_3$