Explanation:
According to Buoyance equation,
m = ![[m' \times \frac{1 - \frac{d_{a}}{d_{w}}}{1 - \frac{d_{a}}{d}}]](https://tex.z-dn.net/?f=%5Bm%27%20%5Ctimes%20%5Cfrac%7B1%20-%20%5Cfrac%7Bd_%7Ba%7D%7D%7Bd_%7Bw%7D%7D%7D%7B1%20-%20%5Cfrac%7Bd_%7Ba%7D%7D%7Bd%7D%7D%5D)
where, m = true mass
m' = mass read from the balance = 17.320 g
= density of air = 0.0012 g/ml
= density of the balance = 7.5 g/ml
d = density of liquid octane = 0.7025 g/ml
Now, putting all the given values into the above formula and calculate the true mass as follows.
m =
= ![[17.320 g \times \frac{1 - \frac{0.0012 g/ml}{7.5 g/ml}}{1 - \frac{0.0012 g/ml}{0.7025}}]](https://tex.z-dn.net/?f=%5B17.320%20g%20%5Ctimes%20%5Cfrac%7B1%20-%20%5Cfrac%7B0.0012%20g%2Fml%7D%7B7.5%20g%2Fml%7D%7D%7B1%20-%20%5Cfrac%7B0.0012%20g%2Fml%7D%7B0.7025%7D%7D%5D)
= 
= 17.317 g
Thus, we can conclude that the true mass of octane is 17.317 g.
Answer:
1) It is the number of particles in one mole of substance. It is an arbitrary definition to denote an amount of substance, not by its weight but by its number of molecules. Why? because that is convenient when doing certain calculations involving molecule formulas.
2) 1 mole of substance contains exactly as many particles as there are atoms in 12 grams of carbon-12.
3) The unified atomic mass unit is 1/12 of the mass of 1 carbon-12 atom.
So you see all three concepts are linked together.
Answer:
Mass of NaF in 250 g tube of toothpaste = 100 mg of NaF
Explanation:
Mass of fluoride per gram of toothpaste = 1 mg
From the given data, the fluoride compound that is most often used in toothpaste is sodium fluoride, NaF, which is 45% fluoride by mass, mass of sodium fluoride per gram of toothpaste can be determined as follows:
1 mg of fluoride per gram of toothpaste = 45% total mass of NaF per gram of toothpaste
100% mass of NaF in toothpaste = 100/45 * 1 mg = 2.22 mg of NaF.
Therefore, mass of NaF per gram of toothpaste is 2.22 mg.
The mass of NaF in 250 g of toothpaste is then calculated below:
In 250 g of toothpaste, mass of NaF = 250 * 2.22 mg = 99.9 mg of NaF
1. true
2. false
3. false
4. true
5.false
6. It's true but can be false because a change in state can be a physical change as well.
Answer:
D . oxidation and reduction oxidation
