Answer:
You can fill 212 balloons.
Explanation:
First we <u>calculate the helium moles in the small cylinder</u>, using <em>PV=nRT:</em>
- P = 14300 kPa ⇒ 14300 * 0.009869 = 141.13 atm
- R = 0.082 atm·L·mol⁻¹·K⁻¹
- T = 25 °C ⇒ 25 + 273.16 = 298.16 K
141.13 atm * 2.20 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K
Then we <u>calculate the number of moles that can fit in a single balloon</u>:
- 1.22 atm * 1.20 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K
Finally we <u>divide the total number of available moles by the number of moles in a single balloon</u>:
- 12.70 mol / 0.0599 mol = 212.09
So the answer is that you can fill 212 balloons.
Answer:
760 uM
Explanation:
<em>A biochemist carefully measures the molarity of magnesium ion in 47, mL of cell growth medium to be 97 uM. Unfortunately, a careless graduate student forgets to cover the container of growth medium and a substantial amount of the solvent evaporates. The volume of the cell growth medium falls to 6.0 mL. Calculate the new molarity of magnesium ion in the cell growth medium Be sure your answer has the correct number of significant digits.</em>
The problem here is that the amount of magnesium ion remains the same irrespective of the volume.
Amount of magnesium in the growth medium = <em>molarity x volume</em>
= 97 x 
x 47 x 
= 4.559 x
Then, the volume reduced to 6.0 mL, the new molarity becomes;
<em>molarity = mole/volume </em>
= 4.559 x /6 x = 7.598333 x 
M = 759.83333 uM
To the correct number of significant digits = 760 uM
Answer: 126.1 grams of are needed to make 5.3 L of 0.25 M solution
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
To calculate the mass of solute for given molarity, we use the equation:
Thus 126.1 grams of are needed to make 5.3 L of 0.25 M solution
The dissociation of both salts NaCl and CaCl₂ are as follows;
NaCl --> Na⁺ + Cl⁻
CaCl₂ --> Ca²⁺ + 2Cl⁻
the molar ratio of NaCl to Cl⁻ is 1:1
therefore number of NaCl moles is equal to number of Cl⁻ ions dissociated from NaCl
then number of Cl⁻ ion moles - 0.233 mol/L x 0.1000 L = 0.0233 mol
molar ratio of CaCl₂ to Cl⁻ ions is 1:2
1 mol of CaCl₂ gives out 2 mol of Cl⁻ ions.
number of CaCl₂ moles - 0.150 mol/L x 0.2500 L = 0.0375 mol
then the number of Cl⁻ ion moles - 0.0375 x 2 = 0.0750
total number of Cl⁻ ion moles = 0.0233 mol + 0.0750 mol = 0.0983 mol
volume of solution - 100.0 + 250.0 = 350.0 mL
concentration of Cl⁻ = 0.0983 mol / 0.3500 L = 0.281 M
concentration of Cl⁻⁻ is 0.281 M
Answer:
False.
Explanation:
all planets have gravity because if they didnt, the gasses and whatever makes up the planet wouldnt be pulled down to the core of the planet, and it would just be floating around in space.
