Part A
75.0 mL of 0.10 M HF; 55.0 mL of 0.15 M NaF
This combination will form a buffer.
Explanation
Here, weak acid HF and its conjugate base F- is available in the solution
Part B
150.0 mL of 0.10 M HF; 135.0 mL of 0.175 M HCl
This combination cannot form a buffer.
Explanation
Here, moles of HF = 0.15 x 0.1 = 0.015 moles
Moles of HCl = 0.135 x 0.175 = 0.023
Since HCl is a strong acid and the number of HCl is higher than HF. This prevents the dissociation of HF and the conjugate base F- will not be available in the solution
Part C
165.0 mL of 0.10 M HF; 135.0 mL of 0.050 M KOH
This combination will form a buffer.
Explanation
Moles of HF = 0.165 x 0.1 = 0.0165 moles
Moles of KOH = 0.135 x 0.05 = 0.00675 moles
Moles of KOH is not sufficient for the complete neutralization of HF. Thus weak acid HF and its conjugate base F- is available in the solution and form a buffer
Part D
125.0 mL of 0.15 M CH3NH2; 120.0 mL of 0.25 M CH3NH3Cl
This combination will form a buffer
Explanation
Here, weak acid CH3NH3+ and its conjugate base CH3NH2 is available in the solution and form a buffer
Part E
105.0 mL of 0.15 M CH3NH2; 95.0 mL of 0.10 M HCl
This combination will form a buffer
Explanation
Moles of CH3NH2 = 0.105 x 0.15 = 0.01575 moles
Moles of HCl = 0.095 x 0.1 = 0.0095 moles
Thus the HCl completely reacts with CH3NH2 and converts a part of the CH3NH2 to CH3NH3+. This results weak acid CH3NH3+ and its conjugate base CH3NH2 is in the solution and form a buffer
Answer:
We can seprate oil and water by the process of seprating funnel
The answer:
<span>the overall balanced equation for the precipitation reaction occurring between silver nitrate and calcium bromide:
</span>CaBr2 + AgNO3-----------> AgBr2 + CaNO3, so among the given choices, the
true answe is
<span>agno3(aq)+cabr2(aq) (as reactants)</span>
Options:
monoglycerides
cocamide DEA
folic acid
iron chromium ion
peroxide
lauryl glucoside
disodium phosphate
Answer and Explanation:
The added chemicals are:
- monoglycerides
- folic acid
- iron
- disodium phophates
Monoglycerides are fats added for flavour. Folic cid and iron are vitamins added for nutritional value. disodium phosphate is a food additive for enhancing flavour.
The remaining ingredients are organic based.
The balanced chemical equation that represents the reaction is as follows:
<span>SrBr2(aq) + 2AgNO3(aq) → Sr(NO3)2(aq) + 2AgBr(s)
</span>
From the periodic table:
mass of silver = 108 grams
mass of bromine = 80 grams
molar mass of silver bromide = 108 + 80 = 188 grams
number of moles = mass / molar mass
number of moles of produced precipitate = 3.491/188 = 0.018 moles
From the balanced equation:
1 mole of strontium bromide produces 2 moles of silver bromide. Therefore, to calculate the number of moles of <span>strontium bromide that produces 0.018 moles of silver bromide, you will just do a cross multiplication as follows:
amount of </span><span>strontium bromide = (0.018x1) / 2 = 9.28 x 10^-3 moles</span>
