M_Quiz_1

X and Y are elements of the third period.

X and Y are individually heated in excess chlorine. Each product is purified and then separately added to water, producing two solutions. Both solutions have a pH of less than 5. What could be X and Y

• Na and P

• Mg and Al

• Mg and Si

• Si and P

An ore contains magnesium carbonate and barium carbonate. A sample of the ore is dissolved in nitric acid.

How could this solution be processed into a magnesium compound and a separate barium compound?

• Add HCl _(aq), filter off the solid barium chloride.

• Add HCl _(aq), filter off the solid magnesium chloride.

• Add H₂SO_{4 (aq)}, filter off the solid barium sulphate.

• Add H₂SO_{4 (aq)}, filter off the solid magnesium sulphate.

When calcium and calcium hydride, CaH₂, react separately with water, they each produce a white solid and a colourless gas. The white solid is the same compound in each reaction.

Which statement is correct?

• Both Ca and CaH₂ produce H₂.

• Both Ca and CaH₂ produce O₂.

• Ca produces H₂ and CaH₂ produce O₂.

• Ca produces O₂ and CaH₂ produce H₂.

When concentrated sulfuric acid is added to solid sodium chloride, HCl is formed but not Cl₂.

When concentrated sulfuric acid is added to solid sodium iodide, I₂ is formed. Which statement explains these observations?

• Sulfuric acid is an oxidising agent and chloride ions are more easily oxidized.

• Sulfuric acid is an oxidising agent and iodide ions are more easily oxidized.

• Sulfuric acid is a reducing agent and chloride ions are more easily reduced.

• Sulfuric acid is a reducing agent and iodide ions are more easily reduced.

The gaseous products of heating a mixture of Ca(OH)₂ and NH₄Cl are passed through solid CaO. This absorbs water vapour and a gas, W, is collected.

A sample of W is oxidized by Cl_2(g) to produce two gases, X and Y. X is an element. Y is acidic. Y reacts with W to produce Z. What are X and Z?

• X is N_{2 ,} Z is CaCl₂

• X is N_{2 ,} Z is NH₄Cl

• X is O_{2 ,} Z is CaCl₂

• X is O_{2 ,} Z is NH₄Cl

Plaster of Paris is chemically:

• CaO

• CaSO₄

• CaSO₄.1 1/2H₂O

• (CaSO₄)2 H₂O

This element is present in insulin:

• Cu

• Fe

• Mg

• Zn

Laughing gas is a:

• general anesthetic

• caustic

• disinfectan

• local anesthetic

Most active of metallic elements:

• alkali metals

• oxidizing agent

• base metals

• solubilizing agent

Hard water does not lather with soap. This is due to:

• K

• Al and O

• Mg and Ca

• Zn and Pb