Answer:
The real answer for a is-He(helium)4,002602
The answer for b is-Mg(Magnesium) 24.305
The answer is 0.5010
Number of moles (n) is equal to the quotient of mass (m) and molar mass of a sample (Mr):
n = m/Mr
We have:
n = ?
m = 40.10 g
Mr = 80.0432 g/mol
n = 40.10 g : 80.0432 g/mol = 0.5010
<span>40.10 has 4 significant digits,
</span><span>80.0432 has 6 significant digits.
Since 4 is less than 6, we choose 4 </span>significant digits
The question is incomplete, the complete question is:
A chemist prepares a solution of vanadium (III) chloride (VCl3) by measuring out 0.40g of VCl3 into a 50.mL volumetric flask and filling to the mark with distilled water. Calculate the molarity of Cl− anions in the chemist's solution. Be sure your answer is rounded to the correct number of significant digits.
Answer:
0.153M of anions
Explanation:
First we calculate the concentration of the solution. From m/M= CV
m=given mass, M= molar mass, C =concentration of solution, V= volume of solution
Molar mass of compound= 51 + 3(35.5)= 157.5gmol-1
0.4g/157.5gmol-1= C×50/1000
C= 2.54×10-3/0.05= 0.051M
But 1 mole of VCl3 contains 3 moles of anions
Therefore, 0.051M will contain 3×0.051M of anions= 0.153M of anions
Answer:
1. 0.073L
2. 0.028L
3. 0.014L
Explanation:
The volume for the different solutions are obtained as shown below:
1. Mole = 0.53mol
Molarity = 7.25M
Volume =?
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 0.53/7.25
Volume = 0.073L
2. 0.035mol from a 1.25M
Mole = 0. 035mol
Molarity = 1.25M
Volume =?
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 0.035/1.25
Volume = 0.028L
3. Mole = 0.0013mol
Molarity = 0.090M
Volume =?
Molarity = mole /Volume
Volume = mole /Molarity
Volume = 0.0013/0.090
Volume = 0.014L
Answer is
3) how much mass per unit of volume is in a substance
