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: must have THE SAME number of atoms for each element
Explanation: Chemical equations must be balanced -- they must have the same number of atoms of each element on both sides of the equation. As a result, the mass of the reactants must be equal to the mass of the products of the reaction.
It can be an element or a compound
Answer:As you can see from the very different numbers in the boxes above, your age changes (sometimes quite a lot) ... Mercury is the closest planet to the Sun and so has a smaller orbit path – it takes just 88 Earth days
Explanation: