AS Paper Exam Questions

Question 1

How many p-orbitals are occupied by electrons in a sulfur atom?

Answer 1

6

Question 2

O.10g of zinc is added to 15cm^3 of 0.25moldm^-3 aqueous silver nitrate. What is the mass of silver that would be formed?

Answer 2

0.33g

Use Zn as it is the limiting reactant!!

Question 3

How many oxygen atoms are in 120.2g of SiO2?

Answer 3

2.41 x 10^24

Question 4

Predict the shapes of and bond angles in NF3 and BF3 molecules

Why are they different?

Answer 4

NF3 - 107, pyramidal
BF3 - 120, trigonal planar

• NF3 has 3 bonded pairs and 1 lone pair
• lone pairs repel more than bonded pairs
• BF3 has 3 bonded pairs

Question 5

What is the equation for the reaction of an acid with a carbonate?

Write the equation for the reaction of ammonium carbonate with dilute nitric acid

Answer 5

Carbonate + acid -> salt + CO2 + H2O

(NH4)2CO3 + 2HNO3 -> 2NH4NO3 + CO2 + H2O

Question 6

What type of flask could be used to make up a standard solution?

Answer 6

Volumetric flask

Question 7

What is the general equation of an alkane?

Answer 7

CnH2n+2