<span>9370 years
First, you need to determine how many half-lives the sample has undergone. Since 67.7% has been lost, that means that 100% - 67.7% = 32.3% has been retained. So calculate the logarithm to base 2 of 0.323:
log(0.323)/log(2) = -0.490797478/0.301029996 = -1.63039393
The number -1.63039393 tells you that 1.63039393 half-lives have occurred since the mastodon died. A quick sanity check will assure you that this is true. Because after 1 half live, there would be 50% of the carbon-14 remaining. And after another half life, there would be 25% of the original carbon-14 remaining. And since 32.3% is between 25% and 50%, the value of 1.63 half lives is quite reasonable. Now just multiply the number of half lives expended by the half life of carbon-14.
1.63039393 * 5750 = 9374.765097
Rounding to 3 significant figures gives us 9370 years.</span>
Answer: 0.374 mol CO2
Explanation:
We can calculate the number of moles of CO, n, required to produce the specified quantity of heat. This is done by dividing the required released heat, q, by the enthalpy of formation per unit mole of the substance, , based on the chemical equation, such that:
Therefore, 0.374 mol of CO2 must be reacted in order to produce 147 kJ of energy?
Boiling-point elevation is a colligative property.
That means, the the boiling-point elevation depends on the molar content (fraction) of solute.
The dependency is ΔTb = Kb*m
Where ΔTb is the elevation in the boiling point, kb is the boiling constant, and m is the molality.
A solution of 6.00 g of Ca(NO3) in 30.0 g of water has 4 times the molal concentration of a solution of 3.00 g of Ca(NO3)2 in 60.0 g of water.:
(6.00g/molar mass) / 0.030kg = 200 /molar mass
(3.00g/molar mass) / 0.060kg = 50/molar mass
=> 200 / 50 = 4.
Then, given the direct proportion of the elevation of the boiling point with the molal concentration, the solution of 6.00 g of CaNO3 in 30 g of water will exhibit a greater boiling point elevation.
Or, what is the same, the solution with higher molality will have the higher boiling point.
Answer:
Carbon dioxide can be collected over water. Carbon dioxide is slightly soluble in water and denser than air, so another way to collect it is in a dry, upright gas jar.
Explanation:
What am I suppose to do???