Answer:
pH of resulting solution = 7.98
Explanation:
The balanced equation
HA + NaOH - Na+ + A- + H2O
Number of moles of A = Number of moles of HA = Number of moles of NaOH
= 35.8/1000 * 0.020 = 0.000716 mol
Initial concentration of A = 0.000716/0.0608 = 0.01178 M
pKb = 14 – pKa = 14 -3.9 = 10.1
Kb = 10^{-Kb} = 10^{-10.1} = 7.943 * 10^-11
Kb = [HA][OH-]/[A-]
Kb = a^2/(0.01178 -a) = 7.943 * 10^-11
a^2 + 7.943 * 10^-11 a – 9.357 * 10^-13 = 0
a = 9.673 * 10^-7
OH- = a = 9.673 * 10^-7 M
pOH = -log [OH-] = -log (9.673 * 10^-7) = 6.02
pH = 14-6.02 = 7.98
<u>Answer:</u> The correct option is C) 1.68 mol/L
<u>Explanation:</u>
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
.....(1)
Given values:
Given mass of 
= 150 g
Molar mass of = 180 g/mol
Volume of the solution = 0.50 L
Putting values in equation 1, we get:
Hence, the correct option is C) 1.68 mol/L
The most stable configuration for Cu (copper) would be 1s2 2s2 2p6 3s2 3p6 4s2 3d9 for the noble gas configuration would be (Ar) 4s2 3d9.
Answer: Decreases the rate of reaction
- Remove water from food by dehydration.
- Transport food in a refrigerated truck.
- Store food in airtight containers.
- Store food in a refrigerator after opening.
Does not decrease the rate of reaction
- Store food in the open air.
- Place food on a warm surface.
Explanation: Dehydration of food excludes water from food which is one of the factor needed by microorganisms for growth, <em>so it decreaese the rate of reaction.</em>
Transporting food in refrigerated trucks lowers the temperature of food and not many microorganisms are active at very low temperatures, so it <em>decreases the rate of reaction.</em>
Storing food in airtight containers excludes air which is one of the factors required for microbial activity, so <em>it decreases reaction rate.</em>
Storing food in refrigerators after opening also <em>lowers the temperature of food and hence the the rate of microbial activit</em>y.
Storing food in the open air <em>does not decrease microbial activity</em> instead it provides microorganisms with the favorable conditions for their activity such as air and water from water vapor in the air.
Placing food on a warm surface <em>does not decrease rate of reaction</em> because microorganisms are very active in warm and humid environments.
Answer:
1.81 x 
molecules H2
Explanation:
Use Avogadro's number:
3 moles H2 x 6.022 x 
molecules= 1.81 x molecules H2
