Answer:
a. The reaction is endothermic.
Explanation:
The heat involved in a chemical reaction is given by the enthalpy change (ΔH), which is equal to the balance between the chemical bonds that are broken (release energy) and the chemical bonds that are formed (need energy):
ΔH ≅ bonds broken - bonds formed
If broken bonds > bonds formed ⇒ ΔH > 0 ⇒ endothermic reaction
Therefore, the reaction is endothermic (it requires energy).
Answer:

Explanation:
Hello
In this case, given the reaction:

It means that since the coefficients preceding phosphorous and phosphorous trifluoride are 1 and 4, the correct mole ratio should be:

Because given the mass of phosphorous it is convenient to convert it to moles and then cancel it out with the moles on bottom of the mole ratio.
Bes regards!
The Krebs cycle uses acetyl CoA as a reactant.
500 mg in g :
1 g ----------- 1000 mg
? -------------- 500 mg
500 x 1 / 1000 => 0.5 g
total mass:
50 g + 0.5 g + 0.1 g => 50.6 g
hope this helps!
Answer:
0.00268 M
Explanation:
To find the new molarity, you need to (1) find the moles of CuSO₄ (via the molarity equation using the beginning molarity and volume) and then (2) find the new molarity (using the moles and combined volume). Your final answer should have 3 sig figs to match the given values.
<u>Step 1:</u>
3.00 mL / 1,000 = 0.00300 L
Molarity = moles / volume (L)
0.0250 M = moles / 0.00300 L
(0.0250 M) x (0.00300 L) = moles
7.50 x 10⁻⁵ = moles
<u>Step 2:</u>
25.0 mL / 1,000 = 0.0250 L
0.0250 L + 0.00300 L = 0.0280 L
Molarity = moles / volume (L)
Molarity = (7.50 x 10⁻⁵ moles) / (0.0280 L)
Molarity = 0.00268 M