Some things that can indicate a chemical change are change of odor, change of color, change in temperature or energy, such as the production or loss of heat. An example could be the rusting of metal, there would be a color change of going from a shiny silver to a dirty, splotchy red color. Some things that indicate a physical change are change of appearance like change of shape, etc. It can also be like a change between a solid to liquid to gas. For example, the cutting of a piece of paper.
Answer:
0.84 moles of oxygen are required.
Explanation:
Given data:
Mass of CO₂ produced = 37.15 g
Number of moles of oxygen = ?
Solution:
Chemical equation:
C + O₂ → CO₂
Number of moles of CO₂:
Number of moles = mass/molar mass
Number of moles = 37.15 g/ 44 g/mol
Number of moles = 0.84 mol
Now we will compare the moles of oxygen and carbon dioxide.
CO₂ : O₂
1 : 1
0.84 : 0.84
0.84 moles of oxygen are required.
Answer:
Strong acids react faster where as weak acids take time to react with any base.
Answer:
Na₂CO₃•H₂O
Explanation:
After it is heated, the remaining mass is the mass of sodium carbonate.
30.2 g Na₂CO₃
Mass is conserved, so the difference is the mass of the water:
35.4 g − 30.2 g = 5.2 g H₂O
Convert masses to moles:
30.2 g Na₂CO₃ × (1 mol Na₂CO₃ / 106 g Na₂CO₃) = 0.285 mol Na₂CO₃
5.2 g H₂O × (1 mol H₂O / 18.0 g H₂O) = 0.289 mol H₂O
Normalize by dividing by the smallest:
0.285 / 0.285 = 1.00 mol Na₂CO₃
0.289 / 0.285 = 1.01 mol H₂O
The ratio is approximately 1:1. So the formula of the hydrate is Na₂CO₃•H₂O.
