25 gigaseconds is equal to 2,500,000,000,000 centiseconds
The molecular weight of K2SO4 is 174.26 g/mole. The mass of K2SO4 required to make this solution is calculated in the following way.
550mL * (0.76mole/1000mL) * (174.26g/mole) = 72.84gram
<span>I hope this helps.</span>
Mass of Oxygen: 0.0159 grams
Moles of Oxygen: 9.94x10^-4
To find the mass of oxygen, subtract the mass of copper from the total mass.

There are 0.0159 grams of Oxygen.
To find how many moles there are, divide the given amount of oxygen by the molar mass (atomic mass) of oxygen because that mass is the same as one mole of oxygen.
Molar mass of Oxygen: 16.00

There are 9.94*10^-4 moles of Oxygen.
Answer:
Explanation:
The melting point of a substance is the temperature at which its melt. The state of a substance is dependent on it's melting temperature. Generally, melting point above 25 °C is a solid.
This means phenol is a solid
Duodecane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of 216 °C means it would require higher temperature to boil it. Since 25 °C is less than 216 °C it means that it would remain in the liquid state.
Methane has melting point below 25 °C hence it is either a liquid or gas. However its boiling point of -164 °C means it boils easily even at very low temperatures. Since 25 °C is greater than -164 °C it means that it would exist in the gaseous state
Density of the gas is 3.05 × 10⁻³ g / cm³.
<u>Explanation:</u>
Volume of the cylinder = π r² h
where r is the radius and h is the height of the height or the length of the glass tube.
Here r = 4 cm and h = 27.4 cm
Volume of the cylinder = 3.14 × 4 × 4 × 27.4 = 1376.6 cm³
We have to find the mass of the gas by subtracting the mass of the tube filled with the substance from the mass of the empty tube.
Mass of the substance = 258.5 - 254.3 = 4.2 g
We have to find the density using the formula as,

Plugin the values as,
= 3.05 × 10⁻³ g / cm³
So the Density of the gas is 3.05 × 10⁻³ g / cm³.