IGCSE Chemistry Paper-1: Specimen Questions with Answers 98 - 99 of 99

Question number: 98

Edit
MCQ▾

Question

Which of the following is a precipitation reaction?

Choices

Choice (4) Response

a.

AgNO₃+NaCl AgCl + NaNO₃

b.

Zn + CuSO₄ + ZnSO₄ + Cu

c.

HCl + NaOH NaCl + H₂O

d.

Question does not provide sufficient data or is vague

Answer

a.

Explanation

A precipitate is a solid that forms out of solution. A common example is that of the mixing of two clear solutions: (1) silver nitrate (AgNO3) and (2) sodium chloride (NaCl): The reaction is.

AgNO₃+NaCl AgCl + NaNO₃

The precipitate forms because the solid (AgCl) is insoluble in water.

Question number: 99

Edit
MCQ▾

Question

Arrange the following elements in the decreasing order of their metallic character.

Cu, Ag, K, Br, Ca

Choices

Choice (4) Response

a.

Br > Ag > Cu > K > Ca

b.

Ca > K > Ag > Cu > Br

c.

K > Ca > Ag > Cu > Br

d.

Question does not provide sufficient data or is vague

Answer

c.

Explanation

Arranging the elements into different groups and periods:

Arrangement of the elements K, Ca, Cu, Br and Ag

Arrangement of the Elements K, Ca, Cu, Br and Ag

Arrangement of elements in group and period

Since the metallic character decreases along a period from left to right, therefore, metallic character decreases in the order K > Ca > Cu > Br.

Since metallic character increases down the group from top to bottom, therefore Ag is more metallic then Cu.