7. The bronze medals are made up of
(a) Cu and Zn (b) Zn and Ni (c) Cu and Sn (d)
Cu, Zn, Tn
8. Silver articles becomes black on
prolonged exposure to air. This is due to the
formation of
(a) Ag20 (b) Ag2s (c) AGCN (d) Ag20 and
Ag2s
Page 2
9. During smelting, an additional substance
is added which combines with impurities to
form a fusible product known as
(a) slag (b) mud (c) gangue (d) flux
10. A student placed an iron nail in copper
sulphate solution. He observed the reddish
brown coating on the iron nail which is
(a) soft and dull (b) hard and flading (c)
smooth and shining (d) rough and granular
11. Which among the following alloys
contain non-metal as one of its constituents?
(a) Brass (b) Amalgam (c) Gun metal (d)
None of these
Answers
Answer:
For the bronze medal, NOCs carefully makes an alloy of copper and other elements, usually tin and zinc, to form a strong bronze medal that is resistant to erosion. The three metal compositions are 97% copper, 2.5% zinc, and 0.5% tin.
This is because the silver metal reacts with sulphur present in the atmosphere and forms silver sulphide (black colour). ... What is the chemical equation of the black coloured layer that is formed on silver because of corrosion? ... Silver articles become black because of the sulphur
slag
rough and glanular
none of the above
please mark it as brainlist
Answer:
Answer
Explanation:
7-: question
Answer - : c
Cu and sn
8-: question
Answer - :
B-: ag2s
9-: question
Answer
A-:slag
10-:question
Answer
D-:rough and granular
11-:question
A-: brass