Answer:
The correct answer is option D.
Explanation:
When a chemical reaction proceeds the reactants are converted into products. The energy hill represents the potential energy of the reaction.
There are two conditions: If the reaction is endothermic than the energy of the products is greater than the energy of the reactants and ΔH is positive. This energy gain is shown in the form of a peak. In an exothermic reaction, the energy of the products is lower than the reactants and ΔH is negative.
So the suitable option is D which states that the reaction is endothermic and the potential energy gained by the products is higher when a reaction proceeds.
They are lost from valence shell (it's outermost shell of an atom).
->>> outside the atom
Explanation:
- It is known that the amount of heat necessary to raise the temperature of 1 gram of a substance by
is known as specific heat.
Since, q = 
So, larger is the specific heat of a substance less will be the change in its temperature.
Therefore, olive oil has less specific heat as compared to water. This means that olive oil would get hotter.
- Similarly, the specific heat of gold is lesser than the given materials or metals. Hence, gold will requires less heat to rise its temperature.
As a result, water present in gold will heat readily.
- As the relation between heat and specific heat is as follows.
q = 
Therefore, calculate the amount of heat required by the water as follows.
q = 
= 
= 33440 J
or, = 33.44 kJ (as 1 kJ = 1000 J)
Thus, 33.44 kJ heat would it take to raise the temperature of 100.0 g of water from
to
.
Answer:
Explanation:
a. NaCl+ AgNO3-----> NaNO3+ AgCl
b. Số mol của NaCl= 0,2*0,5= 0,1 (mol)
------> Số mol của kết tủa AgCl tạo thành= 0,1 mol (dựa vào phương trình hóa học)
-----> Khối lượng của kết tủa AgCl tạo thành= 0,1*143,5=14,35(g)
c. Số mol của AgNO3= số mol của NaCl= 0,1 (mol)
------> Nồng độ mol của dd AgNO3 đã tham gia phản ứng=
=0,25(M)
Answer:
- Mass of monobasic sodium phosphate = 1.857 g
- Mass of dibasic sodium phosphate = 1.352 g
Explanation:
<u>The equilibrium that takes place is:</u>
H₂PO₄⁻ ↔ HPO₄⁻² + H⁺ pka= 7.21 (we know this from literature)
To solve this problem we use the Henderson–Hasselbalch (<em>H-H</em>) equation:
pH = pka + ![log\frac{[A^{-} ]}{[HA]}](https://tex.z-dn.net/?f=log%5Cfrac%7B%5BA%5E%7B-%7D%20%5D%7D%7B%5BHA%5D%7D)
In this case [A⁻] is [HPO₄⁻²], [HA] is [H₂PO₄⁻], pH=7.0, and pka = 7.21
If we use put data in the <em>H-H </em>equation, and solve for [HPO₄⁻²], we're left with:
![7.0=7.21+log\frac{[HPO4^{-2} ]}{[H2PO4^{-} ]}\\ -0.21=log\frac{[HPO4^{-2} ]}{[H2PO4^{-} ]}\\\\10^{-0.21} =\frac{[HPO4^{-2} ]}{[H2PO4^{-} ]}\\0.616 * [H2PO4^{-}] = [HPO4^{-2}]](https://tex.z-dn.net/?f=7.0%3D7.21%2Blog%5Cfrac%7B%5BHPO4%5E%7B-2%7D%20%5D%7D%7B%5BH2PO4%5E%7B-%7D%20%5D%7D%5C%5C%20-0.21%3Dlog%5Cfrac%7B%5BHPO4%5E%7B-2%7D%20%5D%7D%7B%5BH2PO4%5E%7B-%7D%20%5D%7D%5C%5C%5C%5C10%5E%7B-0.21%7D%20%3D%5Cfrac%7B%5BHPO4%5E%7B-2%7D%20%5D%7D%7B%5BH2PO4%5E%7B-%7D%20%5D%7D%5C%5C0.616%20%2A%20%5BH2PO4%5E%7B-%7D%5D%20%3D%20%5BHPO4%5E%7B-2%7D%5D)
From the problem, we know that [HPO₄⁻²] + [H₂PO₄⁻] = 0.1 M
We replace the value of [HPO₄⁻²] in this equation:
0.616 * [H₂PO₄⁻] + [H₂PO₄⁻] = 0.1 M
1.616 * [H₂PO₄⁻] = 0.1 M
[H₂PO₄⁻] = 0.0619 M
With the value of [H₂PO₄⁻] we can calculate [HPO₄⁻²]:
[HPO₄⁻²] + 0.0619 M = 0.1 M
[HPO₄⁻²] = 0.0381 M
With the concentrations, the volume and the molecular weights, we can calculate the masses:
- Molecular weight of monobasic sodium phosphate (NaH₂PO₄)= 120 g/mol.
- Molecular weight of dibasic sodium phosphate (Na₂HPO₄)= 142 g/mol.
- mass of NaH₂PO₄ = 0.0619 M * 0.250 L * 120 g/mol = 1.857 g
- mass of Na₂HPO₄ = 0.0381 M * 0.250 L * 142 g/mol = 1.352 g