Answer:
106 mL
Explanation:
In order to be able to answer this question, you must understand what the density of a substance tells you.
The density of a substance is nothing more than the mass of that substance that occupies one unit of volume.
In your case, the density of ethanol is given in Grams per milliliter, which means that one unit of volume will be
1 mL
.
So, ethanol has a density of
0.785 g mL
−
1
, which is equivalent to saying that if you take exactly
1 mL
of ethanol and weigh it, you will end up with a mass of
0.785 g
.
Now, you know that the volume you're using has a mass of
83.3 g
. Well, if you get
0.785 g
for every
1 mL
of ethanol, it follows that this much mass will correspond to a volume of
83.3
g ethanol
⋅
ethanol's density
1 mL
0.785
g ethanol
=
106.11 mL
Rounded to three sig figs, the answer will be
V
ethanol
=
106 mL
Hope this helps
Answer:
80.1 grams
Explanation:
Find the molar mass of CH3OH first by using the periodic table values.
12.011 g/mol C + (1.008*3 g/mol H) + 15.999g/mol O + 1.008 g/mol H
=32.042 so that is the molar mass
Now that you have 2.50 moles of CH3OH, you can calculate the mass in g
2.50molCH3OH * (32.042g CH3OH / 1 mol CH3OH) = 80.105
32.042g / 1 mol is the same as 32.042 g/mol
Since there are 3 sig figs in the problem (2.50 has 3 sig figs), you round to 80.1 g CH3OH
Protons : positive charge , about same mass as neutrons , in the nucleus
neutrons : no charge , about the same mass as a proton , in the nucleus
electrons : negative charge , less mass than protons and neutrons , in orbitals outside of the nucleus
Atomic mass Ca = 40.078 a.m.u
40.078 g -------------------- 6.02x10²³ atoms
72.8 g ---------------------- ??
72.8 x ( 6.02x10²³) / 40.078 =
4.38x10²⁵ / 40.078 = 1.093x10²⁴ atoms
hope this helps!
Answer:
<h2>13.82 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>13.82 moles</h3>
Hope this helps you
