C. Increase the temperture of the coal
Answer:
73 g Mg(OH)₂
Explanation:
To find the mass of magnesium hydroxide, you need to (1) convert formula units to moles (via Avogadro's number) and then (2) convert moles to grams (via molar mass). Remember to arrange the conversions/ratios in a way that allows for the cancellation of units. The desired unit should be in the numerator. The final answer should have 2 significant figures because the given value (7.5 x 10²³) has 2 sig figs.
Avogadro's number:
6.02 x 10²³ formula units = 1 mole
Molar Mass (Mg(OH)₂):
58.32 g/mol
7.5 x 10²³ units Mg(OH)₂ 1 mole 58.32 g
----------------------------------- x ---------------------------- x -------------------- =
6.02 x 10²³ units 1 mole
= 73 g Mg(OH)₂
Answer:
= 9,593.1 Joules
Explanation:
Heat absorbed by water is equivalent to heat released by copper.
Heat absorbed is given by;
Q = mcΔT
where m is the mass, c is the specific capacity and ΔT is the change in temperature.
Therefore;
Since dnsity of water is 1 g/mL, and specific heat capacity is 4.18 J/g°C while the change in temperature is (75-24) = 51°C.
Heat absorbed by water = 45 g × 4.18 J/g°C × 51
= 9,593.1 Joules
Therefore, the heat released by copper is 9,593.1 Joules
Answer:
Mass = 245.72 g
Explanation:
Given data:
Mass of SrCl₂ react = ?
Mass of H₂SO₄ = 300.0 g
Solution:
SrCl₂ + 2H₂SO₄ → 2HCl + Sr(HSO₄)₂
Number of moles of H₂SO₄:
Number of moles = mass/molar mass
Number of moles = 300.0 g/ 98.079 g/mol
Number of moles = 3.1 mol
Now we will compare the moles of SrCl₂ and H₂SO₄.
H₂SO₄ : SrCl₂
2 : 1
3.1 : 1/2×3.1 = 1.55 mol
Mass of SrCl₂:
Mass = number of moles × molar mass
Mass = 1.55 mol × 158.53 g/mol
Mass = 245.72 g
