The moles which were measured out is calculated using the following formula

moles = mass/molar mass

molar mass of CuBr2.4H20 = 63.5 Cu + ( 2 x79.9) br + ( 18 x4_) h20 = 295.3 g/mol

moles is therefore= 5.2 g/ 295.3 g/mol= 0.0176 moles

4 0

3 years ago

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A small cylinder of helium gas used for filling balloons has a volume of 2.20 L and a pressure of 14300 kPa at 25 ∘C. Part A How

Korvikt [17]

Answer:

You can fill 212 balloons.

Explanation:

First we calculate the helium moles in the small cylinder, using PV=nRT:

P = 14300 kPa ⇒ 14300 * 0.009869 = 141.13 atm

V = 2.20 L

n = ?

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

n = 12.70 mol

Then we calculate the number of moles that can fit in a single balloon:

1.22 atm * 1.20 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K

n = 0.0599 mol

Finally we divide the total number of available moles by the number of moles in a single balloon:

12.70 mol / 0.0599 mol = 212.09

So the answer is that you can fill 212 balloons.

7 0

3 years ago