Distinguish the difference between physical change or chemical change.
Should be C.
Answer: Option (b) is the correct answer.
Explanation:
As on increasing the temperature, the molecules gain more kinetic energy due to which they tend to collide and move rapidly from one place to another.
Thus, we can conclude that when temperature is increased, the kinetic energy of the molecules increases.
This means that temperature is directly proportional to the average kinetic energy of a gas.
Answer:
Mass % of hydrogen = 20.9 %
Explanation:
Given data:
Mass of hydrogen = 0.485 g
Mass of water = 2.32 g
Mass percent of hydrogen = ?
Solution:
Mass % of hydrogen = mass of hydrogen / mass of water × 100
Mass % of hydrogen = 0.485 g/ 2.32 g × 100
Mass % of hydrogen = 0.209 × 100
Mass % of hydrogen = 20.9 %
Answer:
C. 70%
Explanation:
Atomic Mass of the silicon = 28 g.
Atomic mass of the Carbon = 12 g.
Total mass of the Silicon Carbide = 28 + 12
= 40 g.
Now, Using the formula.
% Composition = Mass of the silicon/Total mass of the compound × 100 %
= 28/40 × 100 %
= 70 %
Hence, % composition of the silicon in SiC is 70%
