Answer:
219.78 mL of the stock solution are needed
Explanation:
First, we take a look at the desired Al2(SO4)3 working solution. We are told that the we need 400 mL of an aqueous aluminum sulfate solution 1.0 M. Let's see how many moles of the compound we have in the desired volume:
1000 mL Al2(SO4)3 solution ----- 1 mole of Al2(SO4)3
400 mL Al2(SO4)3 solution ----- x = 0.4 moles of Al2(SO4)3
To reach the desired concentration in the working solution we need 0.4 moles of Al2(SO4)3 in 400 mL, so we calculate the volume of the stock solution needed to prepare the working solution:
1.82 moles Al2(SO4)3/L = 1.82 M → This is the molar concentration of the stock solution.
1.82 moles of Al2(SO4)3 ----- 1000 mL
0.4 moles of Al2(SO4)3 ----- x = 219.78 mL
So, if we take 219.78 mL of the 1.82 M stock solution, we put it in a graduated cylinder and we dilute it to 400 mL, we would obtain a 1.0 M Al2(SO4)3 solution.
Answer:
0.004012km
Explanation:
Problem:
Conversion of millimeters(mm) to Kilometers:
value given = 4012mm
Here, we are converting from a submultiple unit to a multiple unit.
Millimeter depicts 10⁻³m and kilometer stands for 10³m
Now, we must find how many exponents will take us from 10⁻³ to 10³
careful examination shows that if we multiply a power of 10⁶ to 10⁻³ it will give a 10³:
i.e 10⁻³ x 10⁶ = 10⁻³⁺⁶ = 10³
Therefore,
10⁶mm = 1km
4,012mm = 
= 0.004012km
The outer planets of the solar system that are known as Gas Giants
When you boil water, you aren't changing the elements. You're just making water vapor. However, when you burn paper, it becomes carbon (mostly). So physical changes will not change the substance, only chemical changes will.
