Answer:
The number of mol is: 0, 042 mol in 4 grams of MgCl2
Explanation:
We calculate the weight of 1 mol of MgCl2:
Weight 1mol of MgCl2= weight Mg + (weight Cl)x 2=
24, 3 grams + 2 x 35, 5 grams = 95, 3 grams/mol MgCl2
95, 3 grams------1 mol MgCl2
4 grams -------x = (4 grams x1 mol MgCl2)/ 95, 3 grams= 0, 04197 mol MgCl2
To solve this question, you must use the formula: q=mc(change in temperature), where q is heat, m is mass, C is specific heat and temperature change is temperature change. The specific heat for ice is 2.1kJ/Kg x K (given). The change in temperature is 15 degrees Celsius (which you should change to kelvins so you can cancel out units), or 273 + 15 = 288K. The mass is 150 grams, which is 0.15 kg. Now, we can solve for q, heat. We will do this by substituting variables into the formula. After simplifying and cancelling out units, the answer we get is: 90.72kJ.
I believe this is a double replacement. As you can see none of the chemical symbols are missing, there just "replaced".
Answer:
0.04 M
Explanation:
Given data:
Mass of Na₂SO₄= 14.2 g
Volume of solution = 2.50 L
Molarity of solution = ?
Solution:
Number of moles of Na₂SO₄:
Number of moles = mass/ molar mass
Number of moles = 14.2 g/ 142.04 g/mol
Number of moles = 0.1 mol
Molarity :
Molarity = number of moles of solute / volume of solution in L
Molarity = 0.1 mol / 2.50 L
Molarity = 0.04 M
