Which of the following are the bark, roots, seeds, buds or berries of an aromatic plant?

The secondary structure of a protein is distinct from the tertiary structure of a protein mainly because the secondary structure

mixer [17]

Answer:

False

Explanation:

The primary structure of a protein refer to the amino acid sequence. The secondary structure of a protein refer to the alpha helices, beta sheets and turns, while the tertiary structure refer to folding of the sheets due to hydrogen bonding or other bonding interaction between them.

4 0

3 years ago

A solution of phosphoric acid was made by dissolving 10.8 g of H3PO4 in 133.00 mL of water. The resulting volume was 137 mL. Cal

Nesterboy [21]

Answer:

Density is: 1.05 g/ml

Mole fraction solute: 0.015

Mole fraction solvent: 0.095

Molarity: 0.80 M

Molality: 0.82 m

Explanation:

A typical excersise of solution.

It is more confortable to make a table for this.

| masss | volume | mol

solute | | |

solvent | | |

solution | | |

Let's complete, what we have.

| masss | volume | mol

solute | 10.8g | |

solvent | | 133 mL |

solution | | 137 mL |

We can first, know how many moles are 10.8 g

Molar Mass H3PO4 = 97.99 g/mol

Mass / Molar mass = mol

10.8 g / 97.99 g/m = 0.110 mol

Density of water is 1 g/ml (it is a very knowly value)

From this data, we can know water mass, solvent.

Density = mass / volume

1 g/ml = mass / 133 mL

Mass = 133 g

We can also have the moles, by the molar mass of water 18 g/m

133 g / 18 g/m = 7.39 mol

| masss | volume | mol

solute | 10.8g | | 0.110 mol

solvent | 133g | 133 mL | 7.39 mol

solution | 143.8g | 137 mL | 7.50 mol

Mass of solution will be solute mass + solvent mass

Moles of solution will be solute moles + solvent moles

Now we can calculate everything.

Molarity means mol of solute in 1 L of solution. (mol/L)

We have to convert 137 mL in L (/1000)

0.137L so → 0.110 m / 0.137L = 0.80 M

Molality means mol of solute in 1kg of solvent.

We have to convert 133g in kg (/1000)

0.133 kg so → 0.110 m/0.133 kg = 0.82 m

Density is mass / volume

Solution density will be solution mass / solution volume

143.8 g/137 mL = 1.05 g/m

Molar fraction is : solute moles / total moles or solvent moles/total moles.

You can also (x 100%) to have a percent of them.

Remember sum of molar fraction = 1

Molar fraction of solute = 0.110 mol / 7.50mol = 0.015

Molar fraction of solvent = 7.39 mol / 7.50 mol = 0.985

5 0

3 years ago

Consider separate solutions of NaOH and KClmade by dissolving 100.0 g of each solute in 250.0 mL of solution. Calculate the conc

gladu [14]

Answer:

Explanation:

MW of NaOH = 40 g/mol

MW of KCl = 74.55 g/mp;

250 mL = .25 L

100g NaOH / 40 g = 25 mol

100g KCl/ 74.55g = 1.34 mol

Molarity of NaOH: 25/.25 = 100M

Molarity of KCl: 1.34/.25 = 5.36 M

8 0

3 years ago

Compared to the charge of a proton the charge of an electron has

mart [117]

Answer:

Compared to the charge of proton the charge of an electron is negative.

Explanation:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

For example

The carbon have six protons and six neutrons so its atomic mass is 12 amu and atomic number is six.

Electron:

The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.

Symbol= e-

Mass= 9.10938356×10-31 Kg

It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.

Neutron and proton

While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.

Symbol of proton= P+

Symbol of neutron= n⁰

Mass of proton=1.672623×10-27 Kg

Mass of neutron=1.674929×10-27 Kg

5 0

4 years ago

Determine the overall energy change for the reaction between hydrogen and oxygen shown in Question 13. Use Figure 2.

zimovet [89]

Answer:

–500KJ

Explanation:

Data obtained from the question include the following:

Heat of reactant (Hr) = 800KJ

Heat of product (Hp) = 300KJ

Enthalphy change (ΔH) =..?

The enthalphy change is simply defined as the difference between the heat of product and the heat of reactant i.e

Enthalphy change = Heat of product – Heat of reactant

ΔH = Hp – Hr

With the above formula, we can easily calculate the enthalphy change as follow

ΔH = Hp – Hr

ΔH = 300 – 800

ΔH = –500KJ.

Therefore, the overall energy change for the reaction between hydrogen and oxygen shown in the diagram above is –500KJ

5 0

3 years ago