Answer:
pH = 12.15
Explanation:
To determine the pH of the HCl and KOH mixture, we need to know that the reaction is a neutralization type.
HCl + KOH → H₂O + KCl
We need to determine the moles of each compound
M = mmol / V (mL) → 30 mL . 0.10 M = 3 mmoles of HCl
M = mmol / V (mL) → 40 mL . 0.10 M = 4 mmoles of KOH
The base is in excess, so the HCl will completely react and we would produce the same mmoles of KCl
HCl + KOH → H₂O + KCl
3 m 4 m -
1 m 3 m
As the KCl is a neutral salt, it does not have any effect on the pH, so the pH will be affected, by the strong base.
1 mmol of KOH has 1 mmol of OH⁻, so the [OH⁻] will be 1 mmol / Tot volume
[OH⁻] 1 mmol / 70 mL = 0.014285 M
- log [OH⁻] = 1.85 → pH = 14 - pOH → 14 - 1.85 = 12.15
Answer:
For example, friction between our shoes and the floor stop us from slipping and friction between tyres and the road stop cars from skidding. Friction is sometimes unhelpful. For example, if you don't lubricate your bike regularly with oil, the friction in the chain and axles increases.
Explanation:
Answer:
Total percent of magnesium in sample = 25.5%
Explanation:
Given:
Mass of magnesium = 24 gram
Mass of chlorine = 70 gram
Find:
Total percent of magnesium in sample = ?
Computation:
Total mass of sample = Mass of magnesium + Mass of chlorine
Total mass of sample = 24 gram + 70 gram
Total mass of sample = 94 gram
Total percent of magnesium in sample = [Mass of magnesium / Total mass of sample]100
Total percent of magnesium in sample = [24/94]100
Total percent of magnesium in sample = [0.255]100
Total percent of magnesium in sample = 25.5%
Answer:
The new temperature will be 565.83 K.
Explanation:
Gay Lussac's law establishes the relationship between the temperature and the pressure of a gas when the volume is constant. This law says that the pressure of the gas is directly proportional to its temperature. This means that if the temperature increases, the pressure will increase; or if the temperature decreases, the pressure will decrease.
In other words, Gay-Lussac's law states that when a gas undergoes a constant volume transformation, the ratio of the pressure exerted by the gas temperature remains constant:

When an ideal gas goes from a state 1 to a state 2, it is true:

In this case:
- P1= 180 kPa
- T1= 291 K
- P2= 350 kPa
- T2= ?
Replacing:

Solving:

T2= 565.83 K
<u><em>The new temperature will be 565.83 K.</em></u>
Answer:
Ethane would have a higher boiling point.
Explanation:
In this case, for the lewis structures, we have to keep in mind that all atoms must have <u>8 electrons</u> (except hydrogen). Additionally, each carbon would have <u>4 valence electrons</u>, with this in mind, for methane we have to put the hydrogens around the carbon, and with this structure, we will have 8 electrons for the carbon. In ethane, we will have a bond between the carbons, therefore we have to put three hydrogens around each carbon to obtain 8 electrons for each carbon.
Now, the main difference between methane and ethane is an <u>additional carbon</u>. In ethane, we have an additional carbon, therefore due to this additional carbon, we will have <u>more area of interaction</u> for ethane. If we have more area of interaction we have to give <u>more energy</u> to the molecule to convert from liquid to gas, so, the ethane will have a higher boiling point.
I hope it helps!