Answer:
Percent yield = 57.8 %
Theoretical yield = 11.781 g
Explanation:
Given data:
Mass of CaO produced = 6.81 g
Mass of CaCO₃ react = 20.7 g
Theoretical yield = ?
Percent yield = ?
Solution:
Chemical equation:
CaCO₃ → CaO + CO₂
Number of moles of CaCO₃ :
Number of moles = mass/molar mass
Number of moles = 20.7 g/ 100.1 g/mol
Number of moles = 0.21 mol
Now we will compare the moles of CaCO₃ with CaO.
CaCO₃ : CaO
1 : 1
0.21 : 0.21
Theoretical yield of CaO:
Mass = number of moles × molar mass
Mass = 0.21 mol × 56.1 g/mol
Mass = 11.781 g
Percent yield:
Percent yield = ( actual yield / theoretical yield ) × 100
Percent yield = (6.81 g/ 11.781 g) × 100
Percent yield = 57.8 %
Atomic mass C = 12.0107
Atomic mass O= 15.9994
Calculate the molecular mass of the CO2
12.0107 + (2 x 15.9994) = 44.0095
Multiply the mass of CO2 by the conversion factor that relate the O mass to the molecular mass of CO2 to find the mass of O in the 71.89g of CO2
71.89 g CO2 x (2 x 15.9994) / 44.0095 =
52.2703900748702
52.27 g O
Example #1 write the chemical formula for Calcium Oxide
Step 1
-Find the Atomic symbol of the metal and non-metal on the periodic table
CaO
Step 2
Find the charges for Calcium and Oxygen
which are Ca 2+ and O 2-
Step 3
Balance out the charges
They are already balanced out
Here´s the chemical formula for Calcium Oxide
CaO
Example 2 write the chemical formula for Aluminum Oxide
Step 1
-Find the Atomic symbol of the metal and non-metal on the periodic table
A
l
O
Step 2
Find the charges for Aluminum and Oxygen
Which are Al 3+ and O 2-
Step 3
Balance out the charges
You need 2 Aluminum and 3 Oxygen to balance the charges
Al 3+ O 2-
Al 3+ O 2-
= 6 + O 2-
= 6-
Step 4
If you need more then one element to balance out the charges you identify that by using subscripts
Heres your chemical formula for Aluminum Oxide

A.) burning fossil fuels contributes to climate change.
Use this: https://quizlet.com/94519197/bio-ch1-flash-cards/ , it may help