Answer : The correct answer for molarity of MgCl₂ solution is 0.67 M.
Molarity :
It expresses concentration of any solution . It can be defined as mole of solute present in volume of solution in Liter .
It uses unit M or 
It can be formulated as :

Given : mol of MgCl₂ (solute ) = 0.50 mol
Volume of solution = 750 mL
Following steps can be done :
Step 1 ) To convert volume of solution from mL to L
1 L = 1000 mL

Volume of solution = 0.750 L
Step 2) To find molarity
Plugging mole of solute and volume of solution in molarity formula as :


Hence molarity of MgCl₂ solution is 0.67 M
Answer:
Nicolaus Copernicus developed the Heliocentric model for the Solar System in the early 1500s. He was an astronomer, and he published a book in 1532 in which he proposed that the planets orbit the Sun rather than the Earth. The church reacted with outrage, and banned the book.
Answer:
2.31847E25
Explanation:
One mole of anything contains 6.022 x 10^23 items.
Br- < Se2- < As3- < Sr2+ < Rb+
I hope this helps although I'm not a hundred percent sure!