Answer:
Example
0.5 mol of sodium hydroxide is dissolved in 2 dm3 of water. Calculate the concentration of the sodium hydroxide solution formed.
Concentration =
Concentration = 0.25 mol/dm3
Volume units
Volumes used in concentration calculations must be in dm3, not in cm3. It is useful to know that 1 dm3 = 1000 cm3. This means:
divide by 1000 to convert from cm3 to dm3
multiply by 1000 to convert from dm3 to cm3
For example, 250 cm3 is 0.25 dm3 (250 ÷ 1000). It is often easiest to convert from cm3 to dm3 before continuing with a concentration calculation.
Question
100 cm3 of dilute hydrochloric acid contains 0.02 mol of dissolved hydrogen chloride. Calculate the concentration of the acid in mol/dm3.
Reveal answer
Converting between units
The relative formula mass of the solute is used to convert between mol/dm3 and g/dm3:
to convert from mol/dm3 to g/dm3, multiply by the relative formula mass
to convert from g/dm3 to mol/dm3, divide by the relative formula mass
Remember: the molar mass is the Ar or Mr in grams per mol.
Example
Calculate the concentration of 0.1 mol/dm3 sodium hydroxide solution in g/dm3. (Mr of NaOH = 40)
Concentration = 0.1 × 40
= 4 g/dm3
It changes from a liquid from to a solid.
I hope this helps!
The balanced reaction is:
N2 + 3H2 = 2NH3
We are given the amount of the product to be produced.This will be the starting point of our calculations. We use the ideal gas equation to find for the number of moles.
<span>
n = PV / RT = 1.00(.520 L) / (0.08206 atm L/mol K ) 273 K
n= 0.0232 mol NH3
</span>0.0232 mol NH3 (1 mol N2 / 2 mol NH3) = 0.0116 mol N2
<span>Therefore, the correct answer is A.</span>
Answer:
See below.
Explanation:
That is because of the .48.
85.48 is closer to 85 than 86.
