Answer:
20.53 g.
Explanation:
- Knowing that every 15.0 g of pure calcium fluoride contains 7.70 g of calcium.
<u>Using cross multiplication:</u>
15.0 g of pure calcium fluoride contains → 7.70 g of calcium.
40.0 g of pure calcium fluoride contains → ??? g of calcium.
<em>∴ The mass of Ca in 40.0 g of calcium fluoride</em> = (7.70 g)(40.0 g)/(15.0 g) = <em>20.53 g.</em>
Troposphere, this is the layer of the atmosphere closest to the earths crust.
Because their atoms have the same number of electrons in the highest occupied energy level
<span>We know the relation between heat and temperature follows the formula:
Q = Ce * m * (Tf-Ti) , where Q is heat transfer, Ce is specific heat, m is mass, Tf is final temperature and Ti is initial temperature.
Note that heat value is given in kj so we need to change to joules, then as heat is absorbed the final temperature will increase.
4,689 = 0.385 * 34.2 * (Tf-24)
Tf = 4,689 / (0.385 * 34.2) + 24 =380.12ÂşC</span>
Answer:
see below
Explanation:
16. 1 P₄(s) + 6 F₂(g) → 1 PF₃(s)
17. 2 C(s) + 2 H₂O(g) → 1 CH₄(g) + 1 CO₂(g)
18. 2 HgO(s)→ 1 O₂(g) + 2 Hg(l)
19. 1 CaCO₃(s) → 1 CO₂(g) + 1 CaO(s)
