Isotopes are elements that differ in the number in neutrons while the numner of protons are the same. The answers of the questions are: 1) 18/8 O 2) 22/10 Ne 3) 53/25 Mn 4) 37/24 Cr 5) 106/81 Ti.
The answer is 19.9 grams cadmium.
Assuming there was no heat leaked from the system, the heat q lost by cadmium would be equal to the heat gained by the water:
heat lost by cadmium = heat gained by the water
-qcadmium = qwater
Since q is equal to mcΔT, we can now calculate for the mass m of the cadmium sample:
-qcadmium = qwater
-(mcadmium)(0.850J/g°C)(38.6°C-98.0°C)) = 150.0g(4.18J/g°C)(38.6°C-37.0°C)
mcadmium = 19.9 grams
Mass C₂H₂ needed : 22.165 g
<h3>Further explanation</h3>
Reaction
2C₂H₂+
5O₂ ⇒ 4CO₂ + 2H₂O
75.0 grams of CO₂ , mol CO₂ (MW=44 g/mol) :

mol C₂H₂ :

mass C₂H₂ (MW=26 g/mol) :
