Hich of the following statements is true about what happens during a chemical reaction?

Which of the following is not an example of a subatomic particle? electron photon neutron proton

asambeis [7]

I'm pretty sure all 4 are subatomic particles but if i had to guess i'd be Photons

5 0

2 years ago

Read 2 more answers

How many significant figures are in 0.000128?

san4es73 [151]

Three sig figs, the leading zeros are not sig figs

6 0

2 years ago

Which of the following statements is incorrect? A. Molecular mass is expressed in atomic mass units. B. Formula mass compares th

n200080 [17]

Answer:

The incorrect statement is the choice C. Atomic mass has units of grams per atom.

Explanation:

1) Choice A. Molecular mass is expressed in atomic mass units.

Correct. Atomic mass units (a.m.u) is the standard unit used to express the mass of the atoms and the molecules.

Since, one atom, molecule, or formula unit is a tiny amount of material, it has a ver, very low mass, and the unit mass of a molecule is referred to one mole (6.022 × 10²³ units).

2) Choice B. Formula mass compares the mass of one formula unit of a substance to the mass of one atom of carbon-12.

Correct. The masses of atoms and compounds are referred to a standard. Such standard is the carbon-12 atom. This is, the cabon-12 atom was selected as the standard and its exact mass is 12 a.m.u.

3) Choice C. Atomic mass has units of grams per atom.

Incorrect. Atomic mass is the mass of the atoms, but, since, the mass of one atom is so small, the atomic mass is referred to one mole. Hence, the atomic mass has units of grams per mole.

4) Choice D. Both molecular mass and formula mass use carbon-12 as a reference standard.

Correct. As stated when explaining the option B, the mass of atoms, molecules, and formula units are referred to carbon-12 standard.

5) Choice E. Sodium chloride, an ionic compound, is said to have a formula weight, but not a molecular weight.

Correct. The reason is that ionic compounds form large structures (crystals) and, since there is not such thing as one molecule of them, they are said to have formula weight (or mass) but not a molecular weight.

The name molecules is reserved for covalent compounds, where you can formally identify molecules. E.g. Water is a molecular compound, and each molecule has molecular formula H₂O, whose mass is the molecular mass.

7 0

3 years ago

200 g of solid sodium hydroxide (NaOH) are dissolved in 750 mL of water. What is the concentration of this solution?

Anastaziya [24]

Answer:

6.67 M

Explanation:

Molarity = $\frac{mol}{L}$

Convert 200g NaOH to moles. Convert 750 mL to L.

200 g NaOH x (1 mol/39.998 g) = 5.00025... mol NaOH

750 mL x (1 L/1000 mL) = 0.750 L

Substitute values into the equation.

Molarity = $\frac{5.00025}{0.750}$

Molarity = 6.667... M

Molarity = 6.67 M

8 0

2 years ago

True or false: nitrogen gas behaves more like an ideal gas as the temperature increases

navik [9.2K]

Is true. Nitrogen gas behaves more like an ideal gas as the temperature increases. Under normal conditions such as normal pressure and temperature conditions , most real gases behave qualitatively as an ideal gas. Many gases such as air , nitrogen , oxygen ,hydrogen , noble gases , and some heavy gases such as carbon dioxide can be treated as ideal gases within a reasonable tolerance. Generally, the removal of ideal gas conditions tends to be lower at higher temperatures and lower density (that is at lower pressure ), since the work made by the intermolecular forces is less important compared to the kinetic energy of the particles, and the size of the molecules is less important compared to the empty space between them. The ideal gas model tends to fail at lower temperatures or at high pressures, when intermolecular forces and intermolecular size are important.

5 0

3 years ago