The correct answer is A. Brainliest would be much appreciated.
The number is written in scientific notation.
The significant figures are the numbers known precisely plus 1 digit that is uncertain.
When the numbers are expressed in scientific notation all the digits before 10^n are significant.
So, 7 and 8 are significant figures and the answer is that the number of significant figures is 2.
Answer: 2
Answer:
The pitch of the sound a person makes is determined by several factors, including the size and tension of his or her vocal cords.
Explanation:
It would be the top soil. The most dissimilar layer is the uppermost layer.
Excess reactant : Na
NaCl produced : = 16.497 g
<h3>Further explanation</h3>
Given
Reaction(balanced)
2Na + Cl₂⇒ 2NaCl
20 g Na
10 g Cl₂
Required
Excess reactant
NaCl produced
Solution
mol Na(Ar = 23 g/mol) :
= 20 : 23 = 0.87
mol Cl₂(MW=71 g/mol):
= 10 : 71 g/mol = 0.141
mol : coefficient :
Na = 0.87 : 2 = 0.435
Cl₂ = 0.141 : 1 = 0.141
Limiting reactant : Cl₂(smaller ratio)
Excess reactant : Na
Mol NaCl based on mol Cl₂, so mol NaCl :
= 2/1 x mol Cl₂
= 2/1 x 0.141
= 0.282
Mass NaCl :
= 0.282 x 58.5 g/mol
= 16.497 g
