Answer:
C - commas indicate a natural pause in the sentence
Answer:
731.25 g
Explanation:
The question asks us to calculate the mass of 12.5 moles of NaCl. The individual relative atomic masses of the elements were supplied. We must first obtain the molar mass of sodium chloride as follows;
Molar mass of sodium chloride= 23.0 + 35.5 = 58.5 gmol-1
From the formula;
Number of moles (n) = mass /molar mass
Number of moles of sodium chloride= 12.5 moles
Mass of sodium = The unknown
Molar mass of sodium chloride= 58.5gmol-1
Mass of sodium chloride= number of moles × molar mass
Mass of sodium chloride= 12.5 × 58.5
Mass of sodium chloride= 731.25 g
Answer:
The answer is
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Explanation:
To find the number of atoms given the number of moles we use the formula
N = n × L
where
N is the number of entities
n is the number of moles
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question

Substitute the values into the above formula and solve
That's
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We have the final answer as
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Hope this helps you
Answer is: the partial pressure of the helium gas is 0.158 atm.
p(mixture) = 0.48 atm; total pressure.
m(H₂) = 1.0 g; mass of hydrogen gas.
n(H₂) = m(H₂) ÷ M(H₂).
n(H₂) = 1.0 g ÷ 2 g/mol.
n(H₂) = 0.5 mol; amount of hydrogen.
m(He) = 1.0 g; mass of helium.
n(He) = 1 g ÷ 4 g/mol.
n(He) = 0.25 mol; amount of helium.
χ(H₂) = 0.5 mol ÷ 0.75 mol.
χ(H₂) = 0.67; mole fraction of hydrogen.
χ(He) = 0.25 mol ÷ 0.75 mol.
χ(He) = 0.33; mole fraction of helium.
p(He) = 0.33 · 0.48 atm.
p(He) = 0.158 atm; the partial pressure of the helium gas.