Answer:
Average speed = 68 mph
Explanation:
Given that,
Total distance traveled by the family, d = 340 miles
The family traveled 5 hours southeast.
We need to find her average speed. The speed of an object is given by the total distance covered divided by time taken. So,
Put all the values,
So, her average speed is equal to 68 mph.
Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of = 183.511 g/mole
The moles of Cu = 4.7209 moles
From the given chemical formula, we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of = 4.4209 moles
Mass of = Moles of
× Molar mass of
= 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of = 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.