<span>Decomposition reaction.</span>
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
1-pentyne consists of a carbon chain of 5 carbons one with a triple bond. 1-octyne is a carbon chain of 8 carbons with a triple bond at some point. It is known that the longer the carbon chain the higher the boiling point since more energy will be required to break the bonds between carbons. Based on this it is predicted that 1-octyne will have a higher boiling point than 1-pentyne.
I suppose you mean to ask why we can't go through obstacles.
Any atom is surrounded by an electronic cloud. When two atoms get close to each other, the electronic clouds repel each other, preventing them from interpenetrating each other. That same phenomenon, on a larger scale, prevents us from going through matter.
Answer:
d= 50.23 g/cm³
Explanation:
Given data:
radius = 137.9 pm
mass is = 5.5 × 10−22 g
density = ?
Solution:
volume of sphere= 4/3π r³
First of all we calculate the volume:
v= 4/3π r3
v= 1.33× 3.14× (137.9)³
v= 1.33 × 3.14 × 2622362.939 pm³
v= 1.095 × 10∧7 pm³
v= 1.095 × 10∧-23 cm³
Formula:
Density:
d=m/v
d= 5.5 × 10−22 g/ 1.095 × 10∧-23 cm³
d= 5.023 × 10∧+1 g/cm³
d= 50.23 g/cm³
