Answer: The solution to the problem expressed to he correct number of significant figures is 1.69
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule applied for multiplication and division is :
The least precise number determines the number of significant figures in the answer.
As 12.0 has 3 significant digits and 7.11 also has 3 significant digits, the answer would also contain 3 significant digits.
For 
Thus the solution to the problem expressed to he correct number of significant figures is 1.69
Answer: give me more of an explaination
Explanation:
The question can be changed into a new form:
Which element has the most negative electron affinity, or attraction for electrons? halogens have the highest electron affinities, and thus are more attracted to the electrons in the Hydrogen atom than any element in their respective periods.
In this case all the following choices are in the same period, thus Cl or Chlorine is the answer as it is a halogen.
Answer:
a) 1.61 mol
b) Al is limiting reactant
c) HBr is in excess
Explanation:
Given data:
Moles of Al = 3.22 mol
Moles of HBr = 4.96 mol
Moles of H₂ formed = ?
What is limiting reactant =
What is excess reactant = ?
Solution:
Chemical equation:
2Al + 2HBr → 2AlBr + H₂
Now we will compare the moles:
Al : H₂
2 : 1
3.22 : 1/2×3.22 = 1.61 mol
HBr : H₂
2 : 1
4.96 : 1/2×4.96 = 2.48 mol
The number of moles of H₂ produced by Al are less it will be limiting reactant while HBr is present in excess.
Moles of H₂ :
Number of moles of H₂ = 1.61 mol
