Answer:
The balanced equation tells us that 1 mole of Zn will produce 1 mole of H2.
1.566 g Zn x (1 mole Zn / 65.38 g Zn) = 0.02395 moles Zn
0.02395 moles Zn x (1 mole H2 / 1 mole Zn) = 0.02395 moles H2 produced
Now use the ideal gas law to find the volume V.
P = 733 mmHg x (1 atm / 760 atm) = 0.964 atm
T = 21 C + 273 = 294 K
PV = nRT
V = nRT/ P = (0.02395 moles H2)(0.0821 L atm / K mole)(294 K) / (0.964 atm) = 0.600 L
Calcium ions have oxidation state 2+ => Ca (2+).
Bromime ions (bromide) have oxidation state 1- => Br (-).
So, to be neutral the compound has to have two Br (-) ions per each Ca(2+) ion.
That is represented in the chemical formula as Ca Br2, where the number 2 to the right of Br is a subscript meaning that there are two atoms of Br per each atom of Ca (the lack of subscript means 1 atom).
Answer: Ca Br2.
Answer:
1219.5 kj/mol
Explanation:
To reach this result, you must use the formula:
ΔHºrxn = Σn * (BE reactant) - Σn * (BE product)
ΔHºrxn = [1 * (BE C = C) + 2 * (BE C-H) + 5/2 * (BE O = O)] - [4 * (BE C = O) + 2 * (BE O-H).
The BE values are:
BE C = C: 839 kj / mol
BE C-H: 413 Kj / mol
BE O = O: 495 kj / mol
BE C = O = 799 Kj / mol
BE O-H = 463 kj / mol
Now you must replace the values in the above equation, the result of which will be:
ΔHºrxn = [1 * 839 + 2 * (413) + 5/2 * (495)] - [4 * (799) + 2 * (463) = 1219.5 kj/mol
Answer:
6.7 x 10²⁶molecules
Explanation:
Given parameters
Mass of CO₂ = 4.9kg = 4900g
Unknown:
Number of molecules = ?
Solution:
To find the number of molecules, we need to find the number of moles first.
Number of moles = 
Molar mass of CO₂ = 12 + 2(16) = 44g/mol
Number of moles = 
= 111.36mole
A mole of substance is the quantity of substance that contains the avogadro's number of particles.
1 mole = 6.02 x 10²³molecules
111.36 moles = 111.36 x 6.02 x 10²³molecules = 6.7 x 10²⁶molecules
