Answer:
The atomic mass of lead is: 207.216 u
Explanation:
data Isotopes mass percent
1 203.97302 1.4
2 205.974444 24.1
3 206.97587 22.1
4 207.97663 52.4
atomic mass = (203.97302x 0.014) + (205.974444 x 0.241) +
(206.97587 x 0.221) + (207.97663 x 0.524)
atomic mass = 2.856 +49.639 + 45.742 + 108.979
atomic mass = 207.216 u
Answer:
Air is mostly gas
The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of lots of other gases, too, such as carbon dioxide, neon, and hydrogen.
Explanation:
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Answer:
d
Explanation:
Firstly, we need to see the theoretical mole ratio between nitrogen and ammonia from the balanced chemical equation. This is 1 to 2. One mole of nitrogen yielded two moles of ammonia.
At STP, one mole of a gas occupies a volume of 22.4, hence we need to know the volume occupied by a volume of 44.8L of ammonia. This is equal to 44.8/2 = 2 moles
Now we have seen the actual number of moles of ammonia yielded. Since this is the same as the theoretical, it means that only one mole of nitrogen was also used up.
Since it is one mole, the volume at STP is thus 22.4L
Answer : Option D) The pH of the solution is 8.0.
Explanation : pOH of a solution is a measure of hydroxide ion 
concentration in a particular solution. It gives the measure of alkalinity of a solution. Normally, aqueous solutions at 25°C have pOH which is less than 7 are usually alkaline, when pOH is found to be greater than 7 then they are acidic and when pOH will be equal to 7 then it is neutral.
pH + pOH = 14, this relationship is used to find pH of any unknown solution with given pOH value,
Here, we known pOH is 6.0, so we get,
pH = 14 - 6 = 8.0;
Hence, the pH will be 8.0.
