Answer: (a) There are 0.428 moles present in 12 g of 
molecule.
(b) There are 2 moles present in 
particles of oxygen.
Explanation:
(a). The mass of nitrogen molecule is given as 12 g.
As the molar mass of is 28 g/mol so its number of moles are calculated as follows.
So, there are 0.428 moles present in 12 g of molecule.
(b). According to the mole concept, 1 mole of every substance contains 
atoms.
Therefore, moles present in particles are calculated as follows.
So, there are 2 moles present in particles of oxygen.
<span>35 grams
The average salinity of seawater is 35 parts per thousand, so multiply the mass of seawater provided by 0.035 and you'll get the amount of salt (mostly sodium chloride) dissolved in it. So
1000 g * 0.035 = 35 g
Therefore in 1 kilogram of seawater with average salinity, there is 35 grams of salt.</span>
What was the question here?
Full moon I’m pretty sure... good luck!
The neutralization equation is:
3 Ca(OH)₂ + 2 H₃PO₄ → Ca₃(PO₄)₂ + 6 H₂O
From this equation we can see that 3 moles of Ca(OH)₂ react with 2 moles of H₃PO₄
Numbers of mmol of Ca(OH)₂ = M x V = 0.04345 x 54.93 = 2.387 mmol
Number of mmol of H₃PO₄ = 2.387 x (2/3) = 1.591 mmol
Molarity of solution = n (mmol) / V(ml) = 1.591 / 25 = 0.0636 M
