Answer:
ΔH = 180.6 kJ
Explanation:
Given that:
N2 (g) + 2O2(g) = 2NO2 (g) ΔH = 66.4 kJ
<u>2NO (g) + O2 (g) = 2NO2 (g) ΔH = -114.2 kJ </u>
N2 (g) + O2 (g) = 2NO (g) ΔH = ????
The subtraction of both equations would yield the unknown ΔH , therefore:
ΔH = 66.4 - ( - 114.2 kJ)
ΔH = 180.6 kJ
I think the best answer is migration. In an alpine biome, animals have two problems which is the very cold temperature and the UV rays from the sun. Most alpine animals hibernate and migrate to warmer areas of the mountains when the temperature continues to drop.
Answer:
3.65 g / ml correct to 3 sig. fig.
Explanation:
The computation of the concentration required is shown below:
As we know that
[A] = mass of solute ÷ volume of solution
Before that first find the mass of solute
Given that
Initial weight = 5.55g
And,
Final weight = 92.7 g
So,
Mass of KCl is
= 92.7 - 5.55
= 87.15 g ~ 87.2 g
Now the KCi is fully dissolved, so the volume is 23.9 ml
So, concentration is
= 87.2 g ÷ 23.9 ml
= 3.65 g / ml correct to 3 sig. fig.
The number of years required for 1/4 cobalt-60 to remain after decay is calculated as follows
after one half life 1/2 of the original mass isotope remains
after another half life 1/4 mass of original mass remains
therefore if one half life is 5.3 years then the years required
= 2 x 5.3years = 10.6 years
