Heat Transfer Lab
The following represents a lab set up for heat transfer. The cup on the left started with boiling water at 100 degrees C and the cup on the right has water at 20 degrees C. There is an aluminum bar between the two cups allowing heat to transfer from one cup into the other. The set up will be left alone for 20 minutes and temperatures of each cup of water will be recorded every minute for 20 minutes.
mag-aral ka
Water levels tend to drop in dry weather because of evaporation. The hot temperatures will cause the water to achieve its gaseous state and go up into the atmosphere.
Answer : The time passed in years is 
Explanation :
Half-life of carbon-14 = 5730 years
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial amount of the reactant disintegrate = 15.3
a - x = amount left after decay process = 14.8
Now put all the given values in above equation, we get


Therefore, the time passed in years is 
Explanation:
Ok so water is H2O and cabon dioxide in the air is CO2, so the water goes through the carbon dioxide and makes acid rain H2SO4.
Now we have our limestone which is CaCO3.
What happens is that the acid breaks apart our limestone into Ca2+ and CO3 2-. This then reforms into Calcium bicarbonate Ca(CO3)2.
Calcium bicarbonate is soluble in water and is hence washed away by the rain eroding the limestone.
The molecular weight of NaCl is 58.44 g/mol.
0.575 mol * 58.44 g/mol = 33.6 grams of NaCl