The B. atomic mass of an atom is based on the mass of an atom of carbon-12.
The <em>ionic charge</em> depends on the number of <em>electrons</em>.
The <em>atomic number</em> depends on the number of <em>protons</em>.
<em>Isotopes</em> depend on the number of <em>neutrons</em>.
Complete Question
Use the fact that 
to determine how much the pressure must change in order to lower the boiling point of water by a small amount 3.20e-01 K. You may assume that the entropy and density of the liquid and gas are roughly constant for these small changes. You may also assume that the volume per molecule of liquid water is approximately zero compared to that of water vapor, and that water vapor is an ideal gas. Useful constants: Atmospheric pressure is 101300 Pa The boiling point of water at atmospheric pressure is 373.15 K The entropy difference between liquid and gas per kilogram is 6.05e 03 J/kgK The molecular weight of water is 0.018 kg/mol. (a) 0.00e 00 Pa (b) 1.14e 03 Pa (c) 6.85e 26 Pa (d) 4.24e 05 Pa (e) 3.81e 28 Pa
Answer:
Correct option is B
Explanation:
From the question we are told that:
Given Equation
Change of boiling point \triangle 
Generally the equation for Change in time is mathematically given by
Where
And
(from ideal gas equation)
Therefore
Therefore correct option is B
Answer:
0.025g
Explanation:
Firstly, we need to write a balanced chemical equation.
Ca + 2H2O —-> Ca(OH)2 + H2
From the chemical equation, we can see that one mole of calcium metal yielded one mole of hydrogen gas.
Now, we need to know the actual number of moles of hydrogen gas given off.
The number of moles is the mass divided by the atomic mass. The atomic mass of calcium is 40g/mol. The number of moles is thus 0.5/40 = 0.0125 mole
Since the mole ratio is 1:1, the number of moles of hydrogen gas produced too is 0.0125 moles.
We now Proceed to get the mass of the hydrogen gas produced. This is the number of moles of hydrogen multiplied by the molar mass of the diatomic hydrogen gas. The molar mass of the diatomic hydrogen gas is 2g/mol.
The amount given off is thus 2 * 0.0125 = 0.025g
The density increases as the substance cools.
