Copper metal dissolves in concentrated trioxonitrate (V) acid with the resultant evolution of?
CO2
SO2
NO2
CO
Correct answer is C
Oxidation of Copper turnings with concentrated trioxonitrate (V) acid wil
Cu + 4HNO\(_3\) → CuNO\(_3\) + 2H\(_2\)O +2NO\(_2\).
which of the following metals will show the highest metallic character?
Zinc
Copper
Barium
Calcium
Correct answer is C
The reactivity series of metals, also known as the activity series, refers to the arrangement of metals in the descending order of their reactivities.
Na > Ca > Mg > Al > Zn > Fe > Sn > Pb > Cu > Ag.
Considering metallic property which increases down the group, barium will be ranked calcium
Which of the following allotrope of carbon is a constituent of a lead pencil?
Graphite
Diamond
Lampblack
Soot
Correct answer is A
When an element exists in more than one crystalline form, those forms are called allotropes; the two most common allotropes of carbon are diamond and graphite.
Graphite is used in pencils and lubricants. It is a good conductor of heat and electricity. Its high conductivity makes it useful in electronic products such as electrodes, batteries, and solar panels.
The gas that is most useful in protecting humans against solar radiation is?
chlorine
ozone
carbon (IV) oxide
hydrogen sulphide
Correct answer is B
The ozone layer in the stratosphere absorbs a portion of the radiation from the sun, preventing it from reaching the planet's surface.
Most importantly, it absorbs the portion of UV light called UVB.
The gasification of coke is used for the manufacturing of?
producer gas
natural gas
synthetic gas
industrial gas
Correct answer is C
Gasification is a process that converts biomass- or fossil fuel-based carbonaceous materials into synthetic gases