Ask question

Ask question

All categories

2 years ago

15

Sixty-five percent of the mass of bone is a compound called hydroxyapatite. sixty-five percent of the mass of bone is a compound

called hydroxyapatite.
a. True
b. False

1 answer:

mafiozo [28]2 years ago

5 0

True. Its simple how i remeberd was the bone has 650,000 cells and the bone has 65% hydroxyapatite

You might be interested in

In the previous problem, which are the limiting reactants for each reaction? Based on this, calculate the maximum yield of oxyge

juin [17]

please show the previous problem

4 0

3 years ago

2ch4(g) c2h2(g) 3h2(g) describe what is happening within the system when it is at equilibrium in terms of concentrations, reacti

SashulF [63]

Balanced chemical reaction: 2CH₄(g) ⇄ C₂H₂(g) + 3H₂(g).

1) In a chemical reaction, chemical equilibrium is the state in which both reactants (methane CH₄) and products (ethyne C₂H₂ and hydrogen H₂) are present in concentrations which have no further tendency to change with time.

2) At equilibrium, both the forward and reverse reactions are still occurring.

3) Reaction rates of the forward and backward reactions are equal and there are no changes in the concentrations of the reactants and products.

4 0

2 years ago

Read 2 more answers

The gaseous product of a reaction is collected in a 25.0L container at 27.0 C. The pressure in the container is 3.0atm and the g

NeX [460]

Answer: The molar mass of the gas is 31.6 g/mol

Explanation:

According to ideal gas equation:

$PV=nRT$

P = pressure of gas = 3.0 atm

V = Volume of gas = 25.0 L

n = number of moles = ?

R = gas constant = $0.0821Latm/Kmol$

T =temperature = $27.0^0C=(27.0+273)K=300K$

$n=\frac{PV}{RT}$

$n=\frac{3.0atm\times 25.0L}{0.0821 L atm/K mol\times 300K}=3.04moles$

Moles = $\frac{\text {given mass}}{\text {Molar mass}}$

$3.04=\frac{96.0g}{\text {Molar mass}}$

${\text {Molar mass}}=31.6g/mol$

The molar mass of the gas is 31.6 g/mol

4 0

2 years ago

Determine whether or not each ion contributes to water hardness.

Virty [35]

Answer: The ion that contribute to water hardness are:

--> a. Ca2+

--> b. (HCO)3^- and

--> c. Mg2+

While K+ DOES NOT contribute to water hardness.

Explanation:

WATER in chemistry is known as a universal solvent. This is so because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. It is composed of elements such as hydrogen and oxygen in the combined ratio of 2:1.

Water is said to be HARD if it does not lather readily with soap. There are two types of water hardness:

--> Permanent hardness: This is mainly due to the presence of CALCIUM and MAGNESIUM ions in the form of soluble tetraoxosulphate(VI) and chlorides. These ions are removed by adding washing soda or caustic soda.

--> Temporary hardness: This is due to the presence of calcium HYDROGENTRIOXOCARBONATES. It can be removed by boiling and using slaked lime.

Therefore from the above given ions, Ca2+,(HCO)3^- and Mg2+ contributes to water hardness.

4 0

2 years ago

Calculate the amount of energy required to melt 500 g of ice at 0oc. (δhfus=5.96 kj/mole; δhfus is the energy required to melt i

marta [7]

When you want to melt an ice, you only need the latent energy of fusion, <span>δhfus. We use the given value, then multiply this with the given amount to determine the amount of energy. Since the energy is per mole basis, use the molar mass of ice which is 18 g/mol. The solution is as follows:

</span>ΔH = 5.96 kJ/mol * 1 mol/18 g * 500 g
<em>ΔH = 165.56 kJ</em><span>
</span>

3 0

2 years ago