Physical changes can be reversed and chemical changes can’t be reversed. A physical property is a characteristic which can be identified without changing the substance but to identify a chemical property, you do have to change the substance.
Answer:
8.66 g of Al₂O₃ will be produced
Explanation:
4Al (s) + 3O₂ (g) → 2Al₂O₃ (s)
This is the reaction.
Problem statement says, that the O₂ is in excess, so the limiting reactant is the Al. Let's determine the moles we used.
4.6 g / 26.98 g/mol = 0.170 moles
Ratio is 4:2.
4 moles of aluminum can produce 2 moles of Al₂O₃
0.170 moles of Al, may produce (0.170 .2)/ 4 = 0.085 moles
Let's convert the moles of Al₂O₃ to mass.
0.085 mol . 101.96 g/mol = 8.66 g
Answer:
b. 7.5 x 10^-3
Explanation:
To solve this problem we need to keep in mind the <em>definition of molarity</em>:
- Molarity = moles of solute / liters of solution
With the above information in mind it is possible to calculate the moles of solute, given the volume (10 mL) and concentration (0.75 M) of the solution:
- First we<u> convert 10 mL to L</u> ⇒ 10 mL / 1000 = 0.01 L
Then we <u>calculate the moles of AgNO₃</u>:
- moles of solute = Molarity * Liters of solution
- 0.01 L * 0.75 M = 7.5x10⁻³ mol AgNO₃
<em>One mole of AgNO₃ contains one mole of Ag⁺</em>, thus the number of Ag⁺ moles is also 7.5x10⁻³.
Answer:
A hydrocarbon and oxygen
Explanation:
hydrocarbon is being burned, and oxygen is necessary to burn things
