To answer this problem, we write first the stoichiometric equation. Thus we have,
Cu2S + O2 => 2Cu + SO2
Next, we check if the equation is balanced or not.
(left) (right)
2 Cu = 2 Cu
1 S = 1 S
2 O = 2 O
So the stoichiometric equation is balanced, let's proceed in solving the theoretical yield of Cu given 5 g of Cu2S.
First, we solve for Cu2S in moles,
5 g Cu2S x <u>1 mol Cu2S </u> = 0.0314 mol Cu2S
159.16 g Cu2s
Secondly, convert moles of Cu2S to moles Cu. Note for every mole of Cu2S we get 2 moles of Cu. Thus,
0.0314 mo Cu2S x <u> 2 mol Cu </u> = 0.0628 mole Cu<u>
</u> 1 mol Cu2S
Lastly, we convert mole Cu to g Cu via multiplying by Cu's MW.
0.0628 mole Cu x <u>63.546 g Cu </u> = 3.99 g Cu or 4 g Cu<u>
</u> 1 mole Cu
<em>ANSWER: 4 g Cu</em>
Answer:
The balanced chemical equation is given as:

Explanation:
When magnesium metal burns in presence of oxygen it gives white color powdered compound called magnesium oxide.
The balanced chemical equation is given as:

According to reaction, 2 moles of magnesium metal when reacts with 1 mole of oxygen gas it gives 2 moles of solid magnesium oxide.
Answer:
(a) the mass of the water is 3704 g
(b) the mass of the water is 199, 285.7 g
Explanation:
Given;
Quantity of heat, H= 8.37 x 10⁶ J
Part (a) mass of water (as sweat) need to evaporate to cool that person off
Latent heat of vaporization of water, Lvap. = 2.26 x 10⁶ J/kg
H = m x Lvap.

mass in gram ⇒ 3.704 kg x 1000g = 3704 g
Part (b) quantity of water raised from 25.0 °C to 35.0 °C by 8.37 x 10⁶ J
specific heat capacity of water, C, 4200 J/kg.°C
H = mcΔθ
where;
Δθ is the change in temperature = 35 - 25 = 10°C

mass in gram ⇒ 199.2857 kg x 1000 g = 199285.7 g
Tap water and rain water are both homogeneous, even though they may have different levels of dissolved minerals and gases. A bottle of alcohol is a man-made homogeneous mixture, from a fine Italian wine to a glass of Scotch whisky. In the human body, blood plasma is an example of a homogeneous mixture.
Answer:
Because scientists call vaccines reagents.