<u>The addtion of energy</u> <span>is usually needed to help a decomposition reaction occur</span>
Answer:
Mass = 76.176 g
Explanation:
Given data:
Mass of lead(II) chloride produced = 62.9 g
Mass of lead(II) nitrate used = ?
Solution:
Chemical equation:
Pb(NO₃)₂ + 2HCl → PbCl₂ + 2HNO₃
Number of moles of lead(II) chloride:
Number of moles = mass/molar mass
Number of moles = 62.9 g/ 278.1 g/mol
Number of moles = 0.23 mol
Now we will compare the moles of lead(II) chloride with Pb(NO₃)₂ from balance chemical equation:
PbCl₂ : Pb(NO₃)₂
1 : 1
0.23 : 0.23
Mass of Pb(NO₃)₂:
Mass = number of moles × molar mass
Mass = 0.23 mol × 331.2 g/mol
Mass = 76.176 g
Answer: -
A) 3.59
Explanation: -
The number of significant figures in 2.06 = 3
The number of significant figures in 1.743 = 4
The number of significant figures in 1.00 = 3
During multiplication of significant figures, the number of significant figures in the answer would be the smallest value that is 3 in this case.
2.06 x 1.743 x 1.00 = 3.5908.
The answer to 3 significant figures is
2.06 x 1.743 x 1.00 = 3.59
Thus, Andi when performs the calculation that is shown below.
(2.06)(1.743)(1.00)
the answer be reported using the correct number of significant figures as A) 3.59
