Answer:
The recovery of pure caffeine is 67.3% of the original, crude sample.
Explanation:
Step 1: Data given
Mass of pure caffeine = 1.69 grams
Original mass of sample = 2.51 grams
Step 2: What is the percent recovery of pure caffeine from crude?
Percentage = (mass of recovery / original mass) *100%
Percentage = (1.69 grams/2.51 grams) *100%
Percentage = 67.3 %
The recovery of pure caffeine is 67.3% of the original, crude sample.
Answer:
9.96 moles of oxygen
Explanation:
Given data:
Number of molecule of oxygen = 6.00×10²⁴ molecules
Number of moles of oxygen = ?
Solution:
1 mole contain 6.022 ×10²³ molecules
6.00×10²⁴ molecules × 1 moles of oxygen / 6.022 ×10²³ molecules
0.996×10¹ moles of oxygen
9.96 moles of oxygen
The number 6.022 × 10²³ is called Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
Answer:Serkan teacher regularly buys 75 TL of gasoline in his car every week.
At the end of the 13th week, how much is the total gasoline expenditure made by the serkan teacher?
A)390 B)420 C)900 D)975
Explanation:
