Answer:
Sirius B is primarily made out of a carbon-oxygen mixture that was generated by helium fusion in the progenitor star. The outer atmosphere is now almost pure hydrogen, the element with the lowest mass.
Explanation:
Answer:
ΔrxnH = -580.5 kJ
Explanation:
To solve this question we are going to help ourselves with Hess´s law.
Basically the strategy here is to work in an algebraic way with the three first reactions so as to reprduce the desired equation when we add them together, paying particular attention to place the reactants and products in the order that they are in the desired equation.
Notice that in the 3rd reaction we have 2 mol Na₂O (s) which is a reactant but with a coefficient of one, so we will multiply this equation by 1/2-
The 2nd equation has Na₂SO₄ as a reactant and it is a product in our required equation, therefore we will reverse the 2nd . Note the coefficient is 1 so we do not need to multiply.
This leads to the first equation and since we need to cancel 2 NaOH, we will nedd to multiply by 2 the first one.
Taking 1/2 eq 3 + (-) eq 2 + 2 eq 1 should do it.
Na₂O (s) + H₂ (g) ⇒ 2 Na (s) + H₂O(l) ΔrxnHº = 259 / 2 kJ 1/2 eq3
+ 2NaOH(s) + SO₃(g) ⇒ Na₂SO₄ (s) + H₂O (l) ΔrxnHº = -418 kJ - eq 2
+ 2Na (s) + 2 H₂O (l) ⇒ 2 NaOH (s) + H₂ (g) ΔrxnHº = -146 x 2 2 eq 1
<u> </u>
Na₂O (s) + SO₃ (g) ⇒ Na₂SO₄ (s) ΔrxnHº = 259/2 + (-418) + (-146) x 2 kJ
ΔrxnH = -580.5 kJ
Answer:
Disagree.
Explanation:
Nothing would remain. Everything on Earth is made up of atoms. The chair consists of only atoms. So, if you remove all of the atoms, nothing would be left! Hope this helps.
To find the number of neutrons, subtract the number of protons from the mass number. number of neutrons=40−19=21.
Answer:
Decomposition
Explanation:
If we look at the process;
2 NaHCO3 (s) → Na2CO3 (s) + H2O (g) + CO2 (g)
We can see that NaHCO3 was broken down into Na2CO3, H2O and CO2.
The breakdown of one compound to yield other chemical compounds is known as decomposition.
Hence the NaHCO3 was decomposed in the process above.
