Answer:
pH = 12.8
Explanation:
HF + NaOH → F⁻ + Na⁺ + H₂O
<em>1 mole of HF reacts with 1 mole of NaOH</em>
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Initial moles of HF and NaOH are:
HF = 0.018L × (0.308mol / L) = 5.544x10⁻³mol HF
NaOH = 0.023L × (0.361mol / L) = 8.303x10⁻³mol NaOH
That means moles of NaOH remains after reaction are:
8.303x10⁻³mol - 5.544x10⁻³mol = <em>2.759x10⁻³moles NaOH</em>
Total volume is 18.0mL + 23.0mL = 41.0mL = 0.0410L
Molar concentration of NaOH is
2.759x10⁻³moles NaOH / 0.0410L = 0.0673M = [OH⁻]
pOH = - log [OH⁻] = 1.17
As pH = 14 - pOH
<em>pH = 12.8</em>
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Answer:
An open system
Explanation:
An open system is a system in which both matter and energy are exchanged freely between the system and the surroundings.
An example is a pot of water boiling on the stove. The surroundings (the stove) can supply heat energy to the water and the water can escape into the atmosphere.
A <em>closed system</em> is a system in which energy but not matter is exchanged freely between the system and the surroundings.
An example is a pressure cooker on the stove. The surroundings (the stove) can supply heat energy to the food inside, but no matter can escape through the closed lid.
An <em>isolated system</em> is a system in which neither energy nor matter can be exchanged between the system and the surroundings.
An example is a thermos of hot soup. The cap prevents matter from escaping and the shiny interior reflects heat back into the soup.
200 ml is 1/5 of a liter, so the answer is five times the number of moles present in the solution. 0.6 moles/0.2 liter = x moles/1.0 liter. Solving for x gives 0.2 x = 0.6 or x = 3.0 M
so the answer is c
Answer:
Eat food
Explanation:
Food contain protein, carbohydrates, fats etc. These nutrients undergoes metabolic process and produced energy in cellular respiration.
There are two types of respiration:
1. Aerobic respiration
2. Anaerobic respiration
Aerobic respiration
It is the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.
Glucose + oxygen → carbon dioxide + water + 38ATP
Anaerobic Respiration
It is the breakdown of glucose molecule in the absence of oxygen and produce small amount of energy. Alcohol or lactic acid and carbon dioxide are also produced as byproducts.
Glucose→ lactic acid/alcohol + 2ATP + carbon dioxide
This process use respiratory electron transport chain as electron acceptor instead of oxygen. It is mostly occur in prokaryotes. Its main advantage is that it produce energy (ATP) very quickly as compared to aerobic respiration.
