Answer: The given quantity is 2 moles of magnesium or 48 g of magnesium.
The unknown quantity is mass of MgO in grams.
Molar mass of MgO = 40 g
Explanation:
As can be seen from the chemical equation, 2 moles of magnesium react with 1 mole of oxygen gas to give 2 moles of MgO.
According to mole concept, 1 mole of every substance weighs equal to its molar mass.
Thus
of magnesium produce=
of MgO.
Molar mass is the mass in grams of 1 mole of the substance.
Thus if 2 moles of MgO weigh= 80 g
1 mole of MgO will weigh=
Thus molar mass of MgO is 40 g.
Answer:
C. density
Explanation:
Density has to do with weight. Hen you pick up the Styrofoam model, you would notice how much more light it is opposed to the granite model.
4% mass / volume :
4 g ---------> 100 mL
1.2 g ------- ? mL
V = 1.2 * 100 / 4
V = 120 / 4
V = 30 mL
hope this helps!