Answer:

Explanation:
To convert form grams to moles, the molar mass must be used. This is the mass (in grams) in 1 mole of a substance.
We can use the values on the Periodic Table. First, find the molar masses of the individual elements: carbon and oxygen.
- C: 12.011 g/mol
- O: 15.999 g/mol
Check for subscripts. The subscript of 2 after O means there are 2 oxygen atoms, so we have to multiply oxygen's molar mass by 2 before adding.
- O₂: 2* (15.999 g/mol)=31.998 g/mol
- CO₂: 12.011 g/mol + 31.998 g/mol =40.009 g/mol
Use the molar mass as a ratio.

Multiply by the given number of grams.

Flip the fraction so the grams of carbon dioxide cancel.



The original measurement of grams has 2 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.
The ten thousandth place has a 5, so we round the 4 to a 5.

2.4 grams of carbon dioxide is about 0.055 moles.
Answer:
H₂Se
Explanation:
A way of estimating the acidity of a weak acid is by analizing the<em> stability of the formed anion</em>. In this case, we should find a Group 6A element that in its anionic forms (HX⁻ and X⁻²) is more stable than HS⁻ and S⁻², thus it would be more acidic in aqueous solution.
The anionic forms of Se are more stable than the forms of S, similarly to how Br⁻ is more stable than Cl⁻.
Answer:
ΔG° = -533.64 kJ
Explanation:
Let's consider the following reaction.
Hg₂Cl₂(s) ⇄ Hg₂²⁺(aq) + 2 Cl⁻(aq)
The standard Gibbs free energy (ΔG°) can be calculated using the following expression:
ΔG° = ∑np × ΔG°f(products) - ∑nr × ΔG°f(reactants)
where,
ni are the moles of reactants and products
ΔG°f(i) are the standard Gibbs free energies of formation of reactants and products
ΔG° = 1 mol × ΔG°f(Hg₂²⁺) + 2 mol × ΔG°f(Cl⁻) - 1 mol × ΔG°f(Hg₂Cl₂)
ΔG° = 1 mol × 148.85 kJ/mol + 2 mol × (-182.43 kJ/mol) - 1 mol × (-317.63 kJ/mol)
ΔG° = -533.64 kJ
Neutralize it with a alkaline