Answer:
1. 80g
2. 1.188mole
Explanation:
1. We'll begin by obtaining the molar mass of CH4. This is illustrated below:
Molar Mass of CH4 = 12 + (4x1) = 12 + 4 = 16g/mol
Number of mole of CH4 from the question = 5 moles
Mass of CH4 =?
Mass = number of mole x molar Mass
Mass of CH4 = 5 x 16
Mass of CH4 = 80g
2. Mass of O2 from the question = 38g
Molar Mass of O2 = 16x2 = 32g/mol
Number of mole O2 =?
Number of mole = Mass /Molar Mass
Number of mole of O2 = 38/32
Number of mole of O2 = 1.188mole
Answer:
7.4.
Explanation:
∵ pH = -log[H₃O⁺].
∴ pH = -log(2.5 x 10⁻⁷) = 6.6.
<em>∵ pH + pOH = 14.</em>
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∴ pOH = 14.0 - pH = 14.0 - 6.6 = 7.4.
Answer:
b. 4.4
Explanation:
pH is related to the concentration of H₃O⁺ through the following equation:
pH = -log([H₃O⁺]) = -log(4 x 10⁻⁵)
pH = 4.4
Answer:

Explanation:
Hello,
In this case, the by mass percent is computed as shown below:

Whereas the solute is the sugar and the solvent the water, therefore, the concentration results:

Best regards.
I'm going to assume that you mean't mole instead of mile. One mole of O2 has approximately the same mass of one "mole" of N2. I say this because if these elements were rounded by their atomic mass, N would stay as 14, O would round up to 16, and we wouldn't; in this case, O2 would have approximately the same mass as F because F rounds up to 19 and the different between O and N is only 2 while the difference between O and F is 3.