Answer:
Wt. Avg. Atomic Weight => 63.35457 amu
Explanation:
Given Isotopic %Abundance fractional Wt Avg
At. Mass (amu) abundance contribution
Cu-63 62.93 69.09 0.6909 43.4783
Cu-65 64.9278 20.0668 0.200668 20.0668
Wt Average of all isotopes = ∑Wt Avg Contributions
= 43.4783 amu + 20.0668 amu = 63.35457 amu
Answer:
D 2,2
Explanation:
We can see that there are 2 chlorines on the reactant side so there has to be a 2 on the product side
Now we have Na + Cl2 --> 2NaCl
The problem now is that there are 2 sodiums on the product side so add a 2 to the Na on the reactant side
2Na + Cl2 --> 2NaCl
Now it's balanced!
Balanced equation: 2Na(s) + Cl₂(g) ---> 2NaCl(s)
when we have STP conditions, we can use this conversion: 1 mol = 22.4 L
first, we have to convert grams to molecules using the molar mass, and then use mole to mole ratio from the balanced equation.
molar mass of Na= 23.0 g/mol
ratio: 2 mol Na= 1 mol Cl₂ (based on coefficients of balanced equation)
calculations:
The answer for this question is 0.8