D.
This is in accordance with the law of conservation of energy.
Answer:
Redox type
Explanation:
The reaction is:
2Cr + 3Fe(NO₃)₂ → 2Fe + 2Cr(NO₃)₃
2 moles of chromium can react to 3 moles of iron (II) nitrate in order to produce 2 moles of iron and 2 moles of chromium nitrate.
If we see oxidation state, we see that chromium changes from 0 to +3
Iron changed the oxidation state from +2 to 0
Remember that elements at ground state has 0, as oxidation state.
Iron is being reduced while chromium is oxidized. Then, the half reactions are:
Fe²⁺ + 2e⁻ ⇄ Fe (Reduction)
Cr ⇄ Cr³⁺ + 3e⁻ (Oxidation)
When an element is being reduced, while another is being oxidized, we are in prescence of a redox reaction.
The compound solubility which will not be affected by a low pH in solution is AgBr.
<h3>What is pH?</h3>
pH is a measure of the acidity or basicity of any solution and according to the pH scale 0 to 6.9 shows the acidity, 7 is neutral and 7.1 to 14 shows the basicity of any solution.
- AgBr is sparingly soluble in water and not soluble in acids, so if we low the pH of the solution towards the acidity its solubility not affected.
- NiCO₃ is a basic salt and and shows solubility in the acidic medium so change in pH will affect its solubility.
- Co(OH)₂ it is also a basic compound and shows its solubility in the acidic medium and get affected when change in pH takes place.
- PbF₂ is a strong base and also shows solubility in the acidic medium easily, so get affected when change in pH takes place.
- In CuS, sulphide is basic ion and whole compound shows solubility in the acidic medium and get affected when low pH of solution takes place.
AgBr is not affected by a low pH in solution.
To know more about solubility, visit the below link:
brainly.com/question/23946616
The number of moles in 3.612 x 10²⁴ molecules of CaO is 6 moles.
<h3>
Number of moles in the molecules</h3>
The number of moles in 3.612 x 10²⁴ molecules of CaO is calculated as follows;
6.02 x 10²³ molecules = 1 mole
3.612 x 10²⁴ molecules = ?
= (3.612 x 10²⁴ ) / (6.02 x 10²³ )
= 6 moles
Thus, the number of moles in 3.612 x 10²⁴ molecules of CaO is 6 moles.
Learn more about number of moles here: brainly.com/question/15356425
Answer:
Option D. 30 mL.
Explanation:
Step 1:
The balanced equation for the reaction. This is given below:
HNO3 + KOH —> KNO3 + H2O
From the balanced equation above,
The mole ratio of the acid, nA = 1
The mole ratio of the base, nB = 1
Step 2:
Data obtained from the question. This include the following:
Volume of base, KOH (Vb) =.?
Molarity of base, KOH (Mb) = 0.5M
Volume of acid, HNO3 (Va) = 10mL
Molarity of acid, HNO3 (Ma) = 1.5M
Step 3:
Determination of the volume of the base, KOH needed for the reaction. This can be obtained as follow:
MaVa / MbVb = nA/nB
1.5 x 10 / 0.5 x Vb = 1
Cross multiply
0.5 x Vb = 1.5 x 10
Divide both side by 0.5
Vb = (1.5 x 10) /0.5
Vb = 30mL
Therefore, the volume of the base, KOH needed for the reaction is 30mL.
