I think it is "Known".
Radioactive decay is measured using a formula where the half-life <span>of an isotope is the time it takes for the original nuclei to decay half of its original amount.</span>
Answer:
The mole fraction of ethanol is 0.6. A 10 mL volumetric pipette must be used for to measure the 10 mL of ethanol. The vessel should be clean and purged.
Explanation:
For calculating mole fraction of ethanol, the amount of moles ethanol must be calculated. Using ethanol density (0.778 g/mL), 10 mL of ethanol equals to 7.89 g of ethanol and in turn 0.17 moles of ethanol. The same way for calculate the amount of water moles (ethanol density=0.997 g/mL). 2 mL of water correspond to 0.11. The total moles are: 0.17+0.11=0.28. Mole fraction alcohol is: 0.17/0.28=0.6
<u>Answer:</u> The mass of calcium chloride present in given amount of solution is 87.5 g
<u>Explanation:</u>
We are given:
Mass of solution = 277.8 grams
Also, 31.5 % (m/m) of calcium chloride in water. This means that 31.5 g of calcium chloride is present in 100 g of solution.
To calculate the mass of calcium chloride in the given amount of solution, we use unitary method:
in 100 g of solution, the mass of calcium chloride present is 31.5 g
So, 277.8 g of solution, the mass of calcium chloride present is 
Hence, the mass of calcium chloride present in given amount of solution is 87.5 g
Answer:
Option C. 13.5 atm
Explanation:
From the question given above, the following data were obtained:
Pressure of Neon (Pₙₑ) = 4.1 atm
Pressure of Argon (Pₐᵣ) = 3.2 atm
Pressure of nitrogen (Pₙ₂) = 6.2 atm
Total pressure (Pₜ) =?
The total pressure in the container can be obtained by adding the pressure of the individual gases. This is illustrated below:
Pₜ = Pₙₑ + Pₐᵣ + Pₙ₂
Pₜ = 4.1 + 3.2 + 6.2
Pₜ = 13.5 atm
Therefore, the total pressure in the container is 13.5 atm
