Trusted since 2008
LoginRegister
Study resources on Kenyaplex

Get ready-made curriculum aligned revision materials

Exam papers, notes, holiday assignments and topical questions – all aligned to the Kenyan curriculum.

Browse exam papers
Or go directly to:
Class notes Holiday assignments Topical questions Other resources

In an experiment a piece of magnesium ribbon was cleaned with steel wool 2.4g of the clean ribbon was placed in a crucible and completely...

In an experiment a piece of magnesium ribbon was cleaned with steel wool 2.4g of the clean ribbon was placed in a crucible and completely burnt in oxygen.after cooling the product weighted 4.0g.
(a)explain why it was necessary to clean the magnesium ribbon?
(b)what observation was made in the crucible after burning?
(c)why was there an increase in mass?
(d)write the equation for reaction which took place in the crucible?
(e)the product in the crucible was shaken with water and filtered. Explain the observation which was made when blue and red litmus papers were dropped into the filtrate.

Answers

collince
a) the ribbon has to be clean to get rid of the already present oxide later that would hinder full reaction intended in the experiment, the oxide coat forms readily because magnesium is highly reactive.

b)there was a collection of white dust or ash and an increase in mass.

c) the observation is made since the initial matter that is magnesium had successfully reacted with oxygen in air to form an oxide, this is evident as oxygen molecules are attached to magnesium thus an increase in mass.

d) on the attached file

e) when magnesium oxide is mixed in water, the readily available hydrogen atoms react with it to form an hydroxide, this is basic in nature thus the reason we will observe a change on the red litmus paper that turns blue, where as the blue litmus paper shows no change.

Croc answered the question on January 4, 2019 at 03:16

Answer Attachments

Next: Mention four benefits of recycling waste production

Previous: Ways through which the government could influence the allocation of resources in a free market economy

View more Chemistry Questions and Answers  |  Return to Questions Index

Exams With Marking Schemes

Related Questions