A penny for the scratch test (low hardness)a hand lens for inspection a peice of tile for a streak test a geologic hammer to test for cleavage of fracture and the pocket knife for the scratch test (high hardness)
Chemical energy is energy stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place. Usually, once chemical energy has been released from a substance, that substance is transformed into a completely new substance.
Answer:
72.4%
Explanation:
Step 1: Write the balanced equation
2 Cu + S ⇒ Cu₂S
Step 2: Calculate the theoretical yield, in moles, from 0.0970 moles of Cu
The molar ratio of Cu to Cu₂S is 2:1.
0.0970 mol Cu × 1 mol Cu₂S/2 mol Cu = 0.0485 mol Cu₂S
Step 3, Convert the theoretical yield to mass
The molar mass of Cu₂S is 159.16 g/mol.
0.0485 mol × 159.16 g/mol = 7.72 g
Step 4: Calculate the percent yield
We will use the following expression.
%yield = experimental yield/theoretical yield × 100%
%yield = 5.59 g/7.72 g × 100% = 72.4%
B because acetic acid is a weak acid and large quantity means you make it become concentrated