Density = Mass / Volume
10.5 = 500 / x
10.5x = 500
x = 50 cm^3 (1 sig fig) volume of the sphere
Volume of a sphere = 4/3 pi r^2
pi = 3.14 r = radius
50 = 4/3 pi r^3
50•3/4 = pi r^3
37.5 = pi r^3
37.5/pi = r^3
11.9 = r^3
cube root(11.9) = r
2.3 = r
Diameter = 2•radius
Diameter = 2 • 2.3
Diameter = 5 cm (1 sig fig) diameter
The volume of air in a person's lungs is about 615 ml, at a pressure of 760 mm Hg. Inhalation occurs when the pressure in the lungs drops to 752 mm Hg. To what volume do the lungs expand?
Answer:
621.5mL
Explanation:
Given parameters:
Initial volume = 615mL
Initial pressure = 760mmHg
Final pressure = 752mmHg
Unknown;
Final volume = ?
Solution:
To solve this problem, we simply apply Boyle's law.
"the volume of a fixed mass of a gas varies inversely as the pressure changes if the temperature is constant".
Mathematically;
P₁V₁ = P₂V₂
P and V are the pressure
1 and 2 are the initial and final states
Now insert the parameters and start;
760 x 615 = 752 x V₂
V₂ = 621.5mL
You basically just multiply those two and you get your answer that simple hope that helps
Answer:
5.3 × 10⁻³ kg
Explanation:
There is some info missing. I think this is the original question.
<em>A chemist adds 135.0 mL of a 0.21 M zinc nitrate (Zn(NO₃)₂) solution to a reaction flask. Calculate the mass in kilograms of zinc nitrate the chemist has added to the flask. Be sure your answer has the correct number of significant digits.</em>
<em />
We have 135.0 mL of a 0.21 M zinc nitrate (Zn(NO₃)₂) solution. The moles of zinc nitrate are:
0.1350 L × 0.21 mol/L = 2.8 × 10⁻² mol
The molar mass of zinc nitrate is 189.36 g/mol. The mass corresponding to 2.8 × 10⁻² moles is:
2.8 × 10⁻² mol × 189.36 g/mol = 5.3 g
1 kilogram is equal to 1000 grams. Then,
5.3 g × (1 kg/1000 g) = 5.3 × 10⁻³ kg
= 1.6686 moles