Answer:
B: The transport oxygen and nutrients around your body and help to get rid of wastes
Explanation:
The circulatory system carries oxygen and nutrients to the body, but it can also help get rid of waste (though that isn't a huge function of it).
1 mole of any substance contains 6.022 × 1023 particles.
⚛ 6.022 × 1023 is known as the Avogadro Number or Avogadro Constant and is given the symbol NA
N = n × NA
· N = number of particles in the substance
· n = amount of substance in moles (mol)
· NA = Avogardro Number = 6.022 × 10^23 particles mol-1
For H2O we have:
2 H at 1.0 each = 2.0 amu
1 O at 16.0 each = 16.0 amu
Total for H2O = 18.0 amu, or grams/mole
It takes 18 grams of H2O to obtain 1 mole, or 6.02 x 1023 molecules of water. Think about that before we answer the question. We have 25.0 grams of water, so we have more than one mole of water molecules. To find the exact number, divide the available mass (25.0g) by the molar mass (18.0g/mole). Watch how the units work out. The grams cancel and moles moves to the top, leaving moles of water. [g/(g/mole) = moles].
Here we have 25.0 g/(18.0g/mole) = 1.39 moles water (3 sig figs).
Multiply 1.39 moles times the definition of a mole to arrive at the actual number of water molecules:
1.39 (moles water) * 6.02 x 1023 molecules water/(mole water) = 8.36 x 1023 molecules water.
That's slightly above Avogadro's number, which is what we expected. Keeping the units in the calculations is annoying, I know, but it helps guide the operations and if you wind up with the unit desired, there is a good chance you've done the problem correctly.
N = n × (6.022 × 10^23)
1 grams H2O is equal to 0.055508435061792 mol.
Then 23 g of H2O is 1.2767 mol
To calculate the number of particles, N, in a substance:
N = n × NA
N = 1.2767 × (6.022 × 10^23)
N= 176.26
N=
Answer:
B
Explanation:
Look on the x-axis for the tick marked "60". This indicates 60 degrees Celsius, which we want. Now, look on the y-axis for the tick marked "60". This indicates 60 grams of 
. Trace along the graph to find where these two places meet at (60, 60).
Now, look for the solubility curve of ; it's the yellow-orange line. Find out what the y-coordinate of the point where x = 60 is on the line: it's around (60, 65).
So, since the point (60, 60) is below the line corresponding to this substance, is unsaturated.
The answer is B.
Answer:
The correct answer is - 29.45 / 100 x 25.6 = 7.5392 grams
Explanation:
It is given in the question that in 100 gms of CaSO4 there are 29.45 grams of Ca present and there is 25.6 gram of total CaSO4 sample present, So, to calculate the exact value of calcium in this given sample is:
mass of Ca = total amount of sample*percentage of calcium in sample /100
M of Ca =25.6*29.45/100
M of Ca = 7.5392 grams
Thus, the correct procedure is given by 29.45 / 100 x 25.6 = 7.5392 grams
