Answer:
0.125 moles
Explanation:
2.8 litres is equivalent to 2.8dm³
At STP,
1 mole = 22.4 dm³
x mole = 2.8 dm³
Cross multiply
22.4x = 2.8
Divide both sides by 22.4
x = 2.8/22.4
x = 0.125
Answer:
200 W
Explanation:
Formula of Power is
P= W/T
where
W= Work and T= Time
so
4000/20 = 200J/s or 200 W
Explanation:
Reaction rate is a measure of speed of a chemical reaction.
Usually, based on rates, reactions can be divided into two parts:
- Slow reactions which usually takes a long time.
- Fast reactions which takes place completely in seconds or microseconds.
Reaction rate can be defined as a change in the concentration of a reactant or product per unit time:
The unit is mol dm⁻³ s⁻¹
Reaction rate = 
The measurement of the reaction rate is based on the disappearance of a reactant or appearance of a product with increasing reaction time.
Learn more:
Reaction rate brainly.com/question/9642960
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<span>Chemical formula of ammonia = NH3
As we can see there are three atoms of hydrogen in one molecule of ammonia.
So in the 200 molecule of ammonia there will be = 200*3 = 600 atoms of hydrogen.
Answer - 600 atoms of hydrogen.</span>