Complete question is;
A drop of water has a volume of approximately 7 × 10⁻² ml. How many water molecules does it contain? The density of water is 1.0 g/cm³.
This question will require us to first find the number of moles and then use avogadro's number to get the number of water molecules.
<em><u>Number of water molecules = 2.34 × 10²¹ molecules</u></em>
We are given;
Volume of water; V = 7 × 10⁻² ml
Density of water; ρ = 1 g/cm³ = 1 g/ml
Formula for mass is; m = ρV
m = 1 × 7 × 10⁻²
m = 7 × 10⁻² g
from online calculation, molar mass of water = 18.01 g/mol
Number of moles(n) = mass/molar mass
Thus;
n = (7 × 10⁻²)/18.01
n = 3.887 × 10⁻³ mol
from avogadro's number, we know that;
1 mol = 6.022 × 10²³ molecules
Thus,3.887 × 10⁻³ mol will give; 6.022 × 10²³ × 3.887 × 10⁻³ = 2.34 × 10²¹ molecules
Read more at; brainly.in/question/17990661
Answer:
This question is incomplete
Explanation:
This question is incomplete. However, the beaker that contained some water before NaOH were added means that the resulting solution in that beaker will be more dilute. When this diluted sodium hydroxide solution is added to HCl (not hci), the reaction below occurs
HCl + NaOH ⇒ NaCl + H₂O
The reaction above is a neutralization reaction. <u>The concentration of the acid (HCl) will reduce when a base (sodium hydroxide) is added and will also reduce more because of the presence of more water (in the base) which normally reduces the concentration of ions present in an acid or a base to become more dilute.</u>
