Answer:
A. 28 years
Explanation:
Applying,
R = R'(2ᵃ/ⁿ).............. Equation 1
Where R = Original sample, R' = Sample left after decay, a = Total time taken to decay, n = half life.
From the question,
Given: R = 12 g, R' = 6 g, a = 28 years.
Substitute into equation 1 and solve for n
12 = 6(2²⁸/ⁿ)
12/6 = 2²⁸/ⁿ
2²⁸/ⁿ = 2
Equation the base,
28/n = 1
n = 28 years.
Hence the half-life is 28 years
Answer:
14.57g
Explanation:
Given parameters:
Mass of dish + ball = 15.6g
Initial volume of water in the cylinder = 26.7mL
Final volume of water in the cylinder = 38.9mL
Mass of dish = ?
Unknown
Mass of the ball = ?
Solution;
Since the mass of ball and dish is 15.6g,
Mass of the ball =Mass of ball + dish - mass of the dish
Insert the parameters and solve;
Mass of the ball = 15.6g - 1.03g = 14.57g
Answer:
Partial pressure of CO₂ is 406.9 mmHg
Explanation:
To solve the question we should apply the concept of the mole fraction.
Mole fraction = Moles of gas / Total moles
We have the total moles of the mixture, if we have the moles for each gas inside. (3.63 moles of O₂, 1.49 moles of N₂ and 4.49 moles of CO₂)
Total moles = 3.63 mol O₂ + 1.49 mol N₂ + 4.49 mol CO₂ = 9.61 moles
To determiine the partial pressure of CO₂ we apply
Mole fraction of CO₂ → mol of CO₂ / Total moles = P. pressure CO₂ / Total P
Partial pressure of CO₂ = (mol of CO₂ / Total moles) . Total pressure
We replace values: (4.49 moles / 9.61 moles) . 871 mmHg = 406.9 mmHg
Answer:
16.933g approximately 17.0 grams
Explanation:
From the simple promotions and given the same compound ascorbic acid (vitamin C)
In the laboratory synthesised ascorbic acid
Mass of carbon = 30.0g
Mas of Oxygen = 40.0g
That is the mass of Oxygen per unit mass of Carbon
Per gram of Carbon we have
(30.0g Carbon)÷30 combines with (40.0g of Oxygen)÷30
That is 4/3g of Oxygen per gram of Carbon
Hence the mass of Oxygen compound that combines with 12.7g of Carbonin natural occurring ascorbic acid (vitamin C) is = 4/3×12.7 = 16.933g approximately 17.0g
