Atomic mass Calcium ( Ca) = 40.078 u.m.a
40.078 g --------------- 6.02x10²³ atoms
187 g ------------------- ??
187 x ( 6.02x10²³) / 40.078 =
1.125x10²⁶ / 40.078 = 2.808x10²⁴ atoms
hope this helps!
Answer: 1. 3.914 × ^10-4 | 2. 4.781 × ^10-1
Explanation:
Answer:
1) Write the balanced equation:
2C2H6 + 7O2 ---> 4CO2 + 6H2O
2) Determine limiting reagent:
C2H6 ⇒ 13.8 g / 30.0694 g/mol = 0.45894 mol
O2 ⇒ 45.8 g / 31.9988 g/mol = 1.4313 mol
C2H6 ⇒ 0.45894 / 2 = 0.22947
O2 ⇒ 1.4313 / 7 = 0.20447
Oxygen is limiting.
3) Determine theoretical yield of water:
The oxygen : water molar ratio is 7 : 6
7 is to 6 as 1.4313 mol is to x
x = 1.2268286 mol of water
4) Convert moles of water to grams:
1.2268286 mol times 18.015 g/mol = 22.1 g (to three sig figs)
Solution to (b):
14.2 g / 22.1 g = 64.2%
Explanation:
