2017 - JAMB Chemistry Past Questions and Answers - page 3

(^{226}{88}Ra) → (^x{86}Rn) + (^4_{2}He)

(^4_{2}He) = alpha particle

considering the summation of the mass number

226 = x + 4

x = 226 + 4

x = 222

Ammonia = NH₃

Recall that

m = (\frac{MmIt}{96500n})

Mm =108, t = 4830s

I = 10A, n = 1

m = 108 × 10 × ((\frac{4830}{96500})) × 1

m = 54.0g

Mass deposited = Mm × (\frac{It}{96500n})

Tin has a melting point of 232° which enables it to be unaffected by air at ordinary temperature coupled with the fact that it also helps in making a good metal for alloying.

Tin is relatively unaffected by both water and oxygen at room temperature due to its low melting point. It does not rust, corrode, or react in any other way. This explains one of its major uses: as a coating to protect other metals.

m = (\frac{Mm \times Q}{96500n

})

where Q = IT

M = Mm × (\frac{Q}{96500n})

where m = mass

Mm = Molar mass

Q = Quantity of electricity

n = number of change= +1

(\frac{M}{Mm}) = mole = (\frac{mass}{Molarmass})

(\frac{M}{Mm}) = (\frac{Q}{96500n})

= (\frac{9650}{96500n}) × 1

= (\frac{1}{10}) = 0.1mol

Alkanes undergoes substitution reaction and it is an example of halogenation substitution reaction.

Reaction of halogen with alkane in the presence of sunlight (ultraviolet) is termed halogenation. Halogenation is an example of substitution reaction. In addition, alkanes only undergo substitution reaction but not addition reaction.

This is any amylase or a mixture of amylases that converts starch to dextrin and maltose.

Alkyl group has the general formula C_nH₂n + 1.

This formed when one hydrogen is removed from the alkane family. It has the general formula C_nH₂n + 1

In the reactant;

Cu₂S

2 Cu - 2(1) = 0

2 Cu = 2

Cu = (\frac{2}{2})

Cu = +1

In the product, Cu

Cu = O

The oxidation number of Cu in Cu₂S and Cu respectively is +1 and 0 respectively

The setup represents the production of sulfur dioxide. And the cylinder marked X is SO₂