PH3
Also known as phosphine
Explanation:
It is known that for
, ppm present in 1
are as follows.
1
= 0.494 ppm
So, 150
= 
= 0.15 
Therefore, calculate the equivalent concentration in ppm as follows.

= 0.074 ppm
Thus, we can conclude that the equivalent concentration in ppm at STP is 0.074 ppm.
Answer: Sodium chloride
Explanation:
Ocean water contains a number of substances. When a substance which has ionic bonds is dissolved in water it takes the form of ions.
The most common ions in ocean water are sodium and chloride. These are the ions formed when common salt, sodium chloride (NaCl) is dissolved in water.
Sodium chloride accounts for about 3% of ocean water by mass.
There are two hydrogen atoms in one molecule of water.
The answer is B) 2
We need to first come up with a balanced equation:
→ 
We know that the molar ratio of hydrogen to oxygen to water now is 4:1:2.
Converting the amount of grams given to moles is as follows:
Hydrogen: 
Oxygen: 
We know now that the limiting reactant is oxygen. We can then know that the number of moles of water are produced are double the number of moles of oxygen used due to the ratio that we established at the beginning - 4:1:2.
So we now can use 6.25 moles of water as the amount produced.
Then we convert moles of water to grams:

Now we know that there are 112.59g of water produced when we start with 50g of hydrogen and 50g of water.