Answer:
13.75
Explanation:
gets halved every 8 days so halved twice
Sodium sulfate, Na₂SO₄, is a strong electrolyte. It means that it dissociates into 2 Na⁺ ions and 1 SO₄⁻ ion when dissolved in water. So, for every 1 mole of Na₂SO₄, there is an equivalent amount of 2 mol Na⁺ ions. The solution is as follows:
Moles of Na⁺ = (1.27 mol Na₂SO₄/L)*(1 L/1000 mL)*(343 mL)*(2 mol Na⁺/1 mol Na₂SO₄)
<em>Moles of Na⁺ = 0.87 mol</em>
Answer:
Explanation:
uestion
If an atom of an element has a mass number of 45 and it has 20 neutrons in its nucleus, what is the atomic number of the
element?
Answer:
1. d. The reaction is spontaneous in the reverse direction at all temperatures.
2. c. The reaction is spontaneous at low temperatures.
Explanation:
The spontaneity of a reaction is associated with the Gibbs free energy (ΔG). When ΔG < 0, the reaction is spontaneous. When ΔG > 0, the reaction is non-spontaneous. ΔG is related to the enthalpy (ΔH) and the entropy (ΔS) through the following expression:
ΔG = ΔH - T. ΔS [1]
where,
T is the absolute temperature (T is always positive)
<em>1. What can be said about an Endothermic reaction with a negative entropy change?</em>
If the reaction is endothermic, ΔH > 0. Let's consider ΔS < 0. According to eq. [1], ΔG is always positive. The reaction is not spontaneous in the forward direction at any temperature. This means that the reaction is spontaneous in the reverse direction at all temperatures.
<em>2. What can be said about an Exothermic reaction with a negative entropy change?</em>
If the reaction is exothermic, ΔH < 0. Let's consider ΔS < 0. According to eq. [1], ΔG will be negative when |ΔH| > |T.ΔS|, that is, at low temperatures.
