Answer:
A. 4.5 mol Mg(OH)₂
B. 6 mol NaOH
Explanation:
Let's consider the following balanced equation.
Mg(NO₃)₂ + 2 NaOH ⇒ Mg(OH)₂ + 2 NaNO₃
PART A
The molar ratio of NaOH to Mg(OH)₂ is 2:1. The moles of Mg(OH)₂ produced from 9 moles of NaOH are:
9 mol NaOH × 1 mol Mg(OH)₂/2 mol NaOH = 4.5 mol Mg(OH)₂
PART B
The molar ratio of NaOH to NaNO₃ is 2:2. The moles of NaOH needed to produce 6 moles of NaNO₃ are:
6 mol NaNO₃ × 2 mol NaOH/2 mol NaNO₃ = 6 mol NaOH
The solubility of gas in water is inversely proportional to the temperature. That means cool waters can hold more gases than hot waters. So when the oceans continue to warm all the green--houses gases present in oceanic waters will be released into to the atmosphere. This would further lead to the heating up of the planet. The global climate would keep changing and the temperature of the planet would increase further. Therefore, when the oceans continue to warm the amount of green-house gases cannot be sequestered by the oceans (as the temperatures are high) and so this would further enhance the greenhouse effect.
Given :
Number of molecules of 
.
To Find :
How many moles are in given number of molecules.
Solution :
We know, in 1 moles of any element/compound contains 
at atoms/molecules.
So, number of moles in 
molecules are :
Therefore, number of moles are 8.97 .
The 2nd one is the right answer
Hope this helped
