We must know that molarity is a unit for concentration and it is expressed as:
molarity = moles / liters
The molarity is 100 millimolar, or 0.1 molar. The volume is 250 ml, or 0.25 liters. Using the formula above, we find the moles of benzoic acid required.
moles = molarity * liters
moles = 0.1 * 0.25
moles = 0.025
Next, we know that the molar mass for benzoic acid is 122.12 g/mol and the moles of a substance are given by:
moles = mass / molar mass
mass = moles * molar mass
mass = 0.025 * 122.12
mass = 3.05 grams
You will need to weigh out 3.05 grams of benzoic acid
Answer:
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Explanation:
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Joules? i m not sure about this E Q U A S I O N
Answer : The mass of helium gas in the balloon is, 1.23 grams.
Explanation : Given,
Volume of helium gas = 6.9 L
First we have to calculate moles of helium gas at STP.
As we know that, 1 mole of substance occupy 22.4 L volume of gas.
As, 22.4 L volume of helium gas present in 1 mole of helium
So, 6.9 L volume of helium gas present in
of helium
Now we have to calculate the mass of helium gas.

Molar mass of He gas = 4 g/mol

Thus, the mass of helium gas in the balloon is, 1.23 grams.
Answer:
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Explanation: