Answer:
B
Explanation:
Isotopy is a phenomenon in which there exists two or more kind of atoms of the same element. These atoms have the same number of protons but different mass numbers. That is, they have the same atomic number but differ only by the number of neutrons in the nucleus of the atom. Now, let us apply this information to the options individually:
A. Is wrong, they are not the same element
B. Is correct. they both belong to the same element hydrogen. Infact, they are named protium and deuterium respectively
C is wrong they are not same element
D is wrong They are not elements at all
E. Is wrong, one is an element, the other is a molecule
Answer:
2.02 g
Explanation:
Molality (m) is the <em>number of moles of solute dissolved in 1 kg (1000 g) of solvent- </em>that is,
<em>
</em>
Our first step is to calculate the moles of NH₃ in 475 grams of methanol, using <u>molality</u> as a conversion factor.
0.250 mol/kg × 0.475 kg = 0.119 mol
This solution contains <u>0.119 moles of NH₃</u>. Now we must convert the moles to grams, using the <u>molar mass of NH₃</u> as a conversion factor
.
17.031 g/mol × 0.119 mol = 2.02 g
Therefore, 2.02 grams of NH₃ must be dissolved in 475 grams of methanol to make a 0.250 m solution.
the ideal gas equation is PV=nRT
where P=pressure
V=Volume
n=no. of moles
R=universal gas constant
T=temperature
The universal gas constant (R) is 0.0821 L*atm/mol*K
a pressure of 746 mmhg =0.98 atm= 1 atm (approx)
T=37 degrees Celsius =37+273=310 K (convert it to Kelvin by adding 273)
V=0.7 L (only getting oxygen, get 21% of 3.3L)
Solution:
(1 atm)(0.7 L)=n(0.0821 L*atm/mol*K)(310 K)
0.7 L*atm=n(25.451 L*atm/mol)
n=0.0275 mole
Answer:
n=0.0275 mole of oxygen in the lungs.
4: The mass amount of protons and neutrons in an atom
We just covered this in my chem class
