Answer:
25.35%
Explanation:
Again let me restate the the equation of the reaction;
H2O (ℓ) + 2 MnO4 - (aq) + 3 CN- (aq) → 2 MnO2 (s) + 3 CNO- (aq) + 2 OH- (aq)
Amount of potassium permanganate reacted = 10.2/1000 * 0.08035 = 8.1957 * 10^-4 moles
If 2 moles of MnO4 - reacts with 3 moles of CN-
8.1957 * 10^-4 moles of MnO4 - reacts with 8.1957 * 10^-4 * 3/2
= 1.229 * 10^-3 moles of CN-
Mass of CN- reacted = 1.229 * 10^-3 moles of CN- * 26.02 g/mol
= 0.03 g
Hence, percentage of the cyanide = 0.03 g/0.1183 g * 100
= 25.35%
Answer:
A) [H3PO4] will increase, [KH2PO4] will decrease, and pH will slightly decrease.
Explanation:
A buffer is a solution which resists changes to its pH when a small amount of acid or base is added to it.
Buffers consist of a weak acid (HA) and its conjugate base (A–) or a weak base and its conjugate acid. Weak acids and bases do not completely dissociate in water, and instead exist in solution as an equilibrium of dissociated and undissociated species. When a small quantity of a strong acid is added to a buffer solution, the conjugate base, A-, reacts with the hydrogen ions from the added acid to form the weak acid and a salt thereby removing the extra hydrogen ions from the solution and keeping the pH of the solution fairly constant. On the other hand, if a small quantity of a strong base is added to the buffer solution, the weak acid dissociates further to release hydrogen ions which then react with the hydroxide ions of the added base to form water and the conjugate base.
For example, if a small amount of strong acid is added to a buffer solution that is 0.700 M H3PO4 and 0.700 M KH2PO4, the following reaction is obtained:
KH₂PO₄ + H+ ----> K+ + H₃PO₄
Therefore, [H₃PO₄] will increase, [KH₂PO₄] will decrease, and pH will slightly decrease.:
The temperature at which phase changes occur is highly dependent on the electrostatic forces between the molecules in the substance.
The forces that hold molecules together are called intermolecular forces. These intermolecular forces affect the temperature at which phase changes occur. The statement about phase changes and electrostatic forces that is correct is that; "the temperatures at which a substance changes phases indicate the relative strength of the forces between molecules in the substance."
There are three states of matter, solid liquid and gas. The order of intermolecular forces in all the states of matter are not the same. The order of strongest collective electrostatic forces to weakest collective electrostatic forces is; solid, liquid, gas.
When water boils, the forces between water molecules break, and the bonds between the atoms in water are unchanged.
When a sample of calcium carbonate is cooled, the forces strengthen, and the molecule structure becomes more rigid.
If the boiling point of acetone is lower than the boiling point of ethanol, then, the intermolecular forces in ethanol are stronger than the intermolecular forces in acetone.
Learn more about phase changes: brainly.com/question/671212