I think the correct answer among the choices presented above is option C. The <span>atomic number of an atom is equivalent to the number of protons in the nucleus. For a neutral atom, it is also the number of electrons since in a neutral atom protons and electrons are present in equal number.</span>
There are 3 sig figs. 8 and 2 are obvious. The ending 0 is significant because it is at the end of a decimal number, and doesn't have to be measured.
PH is a measure of hydrogen(colorless, odorless) concentration of solutions. Ph is in solutions for an example like spray to clean the kitchen counter or table.These things have color and are odorless after a while.
Answer:
12 L of 40% sulfuric acid solution and 8 L of 10% sulfuric acid solution are needed to make 20 L of sulfuric acid solution.
Explanation:
For first solution of sulfuric acid :
C₁ = 40% , V₁ = ?
For second solution of sulfuric acid :
C₂ = 10% , V₂ = ?
For the resultant solution of sulfuric acid:
C₃ = 28% , V₃ = 20L
Also,
<u>V₁ + V₂ = V₃ = 20L</u> ......................................(1)
Using
<u>C₁V₁ + C₂V₂ = C₃V₃</u>
<u>40×V₁ + 10×V₂ = 28×20</u>
So,
40V₁ + 10V₂ = 560........................................(2)
Solving 1 and 2 as:
V₂ = 20 - V₁
Applying in 2
40V₁ + 10(20 - V₁) = 560
40V₁ + 200 - 10V₁ = 560
30V₁ = 360
<u>V₁ = 12 L</u>
So,
<u>V₂ = 20 - V₁ = 8L</u>
<u><em>12 L of 40% sulfuric acid solution and 8 L of 10% sulfuric acid solution are needed to make 20 L of sulfuric acid solution.</em></u>
You should use the joules (J) unit of measurement.