Answer:
Mass = 8 g
Explanation:
Given data:
Mass of MgO formed = 20 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of MgO:
Number of moles = mass/molar mass
Number of moles = 20 g/ 40 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of MgO and O₂ from balance chemical equation:
MgO : O₂
2 : 1
0.5 : 1/2×0.5 = 0.25 mol
Mass of oxygen required:
Mass = number of moles × molar mass
Molar mass of O₂ is 32 g/mol
Mass = 0.25 mol × 32 g/mol
Mass = 8 g
Answer: option 3. 5.46 L
Explanation:
1)<u> Data</u>
2) <u>Chemical principle</u>
<u />
- Combined law for ideal gases:
3) <u>Solution</u>
a) Conversion of units
The ideal gas law is valid for temperature in absolute units (Kelvin); hence, you have to converte °C to K.
- T₁ = 55.0 + 273.15 K = 328.15 K
- T₂ = 59.0 + 273.15 K = 332.15 K
b) Clear V₂ from the combined law of gases
c) Substitute values and compute
The answer must be reported with three significant figures, which is the number used for the data.
Answer: the gas will ocupy 5.46 liter at the new condictions of pressure and temperature.
Answer:
Products.
Explanation:
Products are the substances obtained at the end of a chemical reaction. By modifying the bonds and generating or consuming a certain amount of energy, one or more products will be available.
Question 6
a) B
b) A
Question 7
a) Iron
b) oxygen, water
c) i) Galvanizing
ii) Painting
Answer:
B, a stove
Explanation:
of all the answers, the stove is the only one that is made to transfer electricity to thermal energy.