What percentage of the formula mass of Na2SO4 does sodium constitute?

The number of molecules in 1.0 mole of H2O is the same as in one mole of O2.

zaharov [31]

True. A mole of anything has the same amount of molecules. 1 mole = 6.022 x 1023 molecules

8 0

3 years ago

What is the identity of the element, and how many neutrons does it have? An elements most stable ion forms an ionic compound wit

Pani-rosa [81]

Answer:

B. CA, 14

Explanation:

Atoms of elements contain small particles known as electrons, neutrons, and protons. The nucleus of an atom is made up of neutrons and protons which are at the center of the atom. Electrons on the other hand surrounds the nucleus. Electron has negative charge while proton has a positive charge. The number of neutrons is equivalent to the number of protons . In addition, the number of protons is equal to mass number minus the number of electrons.

For the compound $XCl_{2}$ , it can be broken down into $X^{2+}$ and $2Cl^{-}$ . Its ion has a mass of 34 and 18 electrons which means it has already lost 2 electrons.

Therefore:

For the given element, the number of electrons is 18+2 = 20 electrons.

The number of protons = 34 - 20 = 14.

And the number of neutrons is 14.

Only option B has the correct answer.

6 0

3 years ago

g The reaction; 4 Ag(s) + O2(g) ----> 2 Ag2O(s), is exothermic. Which statement about the reaction is correct? (A) It is spon

melomori [17]

Answer:

The correct answer is B. It is spontaneous only at low temperatures.

Explanation:

In thermodynamics, the Gibbs free energy is a thermodynamic potential that can be used to calculate the maximum of reversible work that may be performed by a thermodynamic system at a constant temperature and pressure.

The spontaneity of a reaction is given by the equation:

ΔG = ΔH - TΔS

where:

ΔH: enthalpy variation

T: absolute temperature

ΔS: entropy variation

As the reaction is exothermic, ΔH<0

As the reaction order increases (the reagents are solid and gas and their product is solid), ΔS<0

Therefore, the reaction will be spontaneous when ΔG is negative.

ΔG = ΔH - TΔS

That is, the entropy term must be smaller than the enthalpy term.

Hence, the reaction will be spontaneous only at low temperatures.

4 0

3 years ago

The graph above plots gravitational force versus distance for two asteroids of equal mass (10 billion kg). When the distance bet

natima [27]

Answer:ABOUT 74 N

Explanation: TOOK THE TEST ON STUDY ISLAND :)

7 0

3 years ago

Read 2 more answers

Acetic acid, CH3COOH, can be produced by bubbling oxygen gas into acetaldehyde, CH3CHO, in the presence of

slamgirl [31]

Explanation:

The balanced equation for the reaction is given as;

2CH3CHO + O2 → 2CH3COOH

If 20.0 g CH3CHO and 10.0 g O2 were put into a reaction vessel, (a)

how many grams of acetic acid will be produced?

First thing's first, we have to find he limiting reactant. This is done by comparing the number of moles of the reactants.

From the equation of the reaction;

2 mol of CH3CHO reacts with 1 mol of O2

From the masses given;

Number of moles = Mass / Molar mass

CH3CHO;

Number of moles = 20 / 44.0526 = 0.454 mol

O2;

Number of moles = 10 / 32 = 0.3125 mol

The limiting reactant is CH3CHO because O2 would be in excess.

Back to the question;

2 mol of CH3CHO produces 2 mol of CH3COOH

0.454 mol would produce x

Solving for x;

x = 0.454 * 2 / 2 = 0.454 mol

Converting to mass;

Mass = number of moles* Molar mass

Mass = 0.454 mol * 60.052 g/mol = 27.26 grams

(b) how many grams of the excess reactant remain after the reaction is

complete

The excess reactant is O2

Number of moles left = Initial Number of moles - Number of moles that reacted

Number of moles left = 0.3125 mol - (0.454 mol / 2)

Number of moles left = 0.0855 mol

Converting to mass;

Mass = 0.0855 mol * 32 g/mol = 2.736 grams

6 0

3 years ago