hi im breanna
Answer:
The mole is simply a very large number that is used by chemists as a unit of measurement.
Explanation:
The mole is simply a very large number,
6.022
×
10
23
, that has a special property. If I have
6.022
×
10
23
hydrogen atoms, I have a mass of 1 gram of hydrogen atoms . If I have
6.022
×
10
23
H
2
molecules, I have a mass of 2 gram of hydrogen molecules. If I have
6.022
×
10
23
C
atoms, I have (approximately!) 12 grams.
The mole is thus the link between the micro world of atoms and molecules, and the macro world of grams and litres, the which we can easily measure by mass or volume. The masses for a mole of each element are given on the periodic table as the atomic weight. So, if have 12 g of
C
, I know, fairly precisely, how many atoms of carbon I have. Given this quantity, I know how many molecules of
O
2
are required to react with the
C
, which I could measure by mass or by volume.
<span>B. muscular endurance
</span>The capacity of a muscle to continue contracting over a period of time without fatigue is called muscular endurance.
NOT:
A. muscular strength.
<span>C. cardiovascular endurance. </span>
<span>D. power.</span>
Since this equation is balanced, we know that the law of conversation of mass id applied, and we could calculate easily.
Na= 2
NO3= 2
Ca= 1
<span>Cl= 1</span>
<u>Answer:</u> The volume of acid and water that must be mixed will be 4.8 L and 11.2 L
<u>Explanation:</u>
We are given:
Volume of mixture = 16 L
Percent of acid present = 30 %
Calculating the percentage of acid present in the mixture:
The mixture is made entirely of acid and water.
Volume of acid in the mixture = 4.8 L
Volume of water in the mixture = 16 - 4.8 = 11.2 L
Hence, the volume of acid and water that must be mixed will be 4.8 L and 11.2 L
The density of the sample is:
Density = mass / volume
Density = 9.85 / 0.675
Density = 14.6 g/cm³
If the sample has 95% gold, and 5% silver, its density should be:
0.95 x 19.3 + 0.05 x 10.5
Theoretical density = 18.9 g/cm³
The difference in theoretical and actual densities is very large, making it likely that the jeweler was not telling the truth.
