Answer:
<h2>
</h2>
Explanation:
<u>First of all cross multiply</u>
That's
<u>Next divide both sides by </u>
<u> in order to isolate </u>
We have
We have the final answer as
Hope this helps you
Answer:
We need 420 cal of heat
Explanation:
Step 1: Data given
Mass of the aluminium = 200.0 grams
Temperature rises with 10.0 °C
Specific heat of aluminium = 0.21 cal/g°C
Step 2: Calculate the amount of heat required
Q =m * c* ΔT
⇒with Q = the amount of heat required= TO BE DETERMINED
⇒with m = the mass of aluminium = 200.0 grams
⇒with c = the specific heat of aluminium = 0.21 cal/g°C
⇒with ΔT = the change of temperature = 10.0°C
Q = 200.0 grams * 0.21 cal/g°C * 10.0 °C
Q = 420 cal
We need 420 cal of heat (option 2 is correct)
Answer : The formula of the gas produced is, 
(phosphine gas)
Explanation :
According to the question, when sodium phosphide is treated with water then it react to give phosphine gas and sodium hydroxide.
The balanced chemical reaction will be:
By Stoichiometry of the reaction we can say that:
1 mole of sodium phosphide reacts with 3 moles of water to give 1 mole of phosphine gas and 3 moles of sodium hydroxide.
Thus, the formula of the gas produced is, (phosphine gas)
Answer:
0.43×10²³ atoms
Explanation:
Given data:
Mass of LiBrO₂ = 4.28 g
Number of atoms of oxygen = ?
Solution:
Number of moles = mass/molar mass
Number of moles = 4.28 g/ 118.84 g/mol
Number of moles = 0.036 mol
We can see 1 mole of LiBrO₂ contain 2 mole of oxygen atm.
0.036 mol × 2 = 0.072 mol
1 mole contain 6.022×10²³ atoms
0.072 mol × 6.022×10²³ atoms / 1mol
0.43×10²³ atoms
