Every time you see molecules, atoms, & particles think of avagadros #. (6.022 x 10^23)
Answer: 13.6 grams of H2O
Solution: (4.56x10^23) x (1 mol H2O/6.022x10^23) x (18 grams H2O/1 mol H2O) = 13.6 grams of H2O
Using dimensional analysis above makes these types of problems easy.
Answer:
18 * 10^19 atoms
Explanation:
We must first convert 57.8 mg to grams.
If 1000 mg = 1g
57.8 mg = 57.8/1000 = 57.8 * 10^-3 g
Now;
If 1 gold atom has a mass of 3.27X10^-22 grams
x gold atoms have a mass of 57.8 * 10^-3 g
x = 57.8 * 10^-3 g/3.27X10^-22 g
x = 18 * 10^19 atoms
Answers a
Explanation
Because it removes all the energy in the form of heat
Answer:
(3) 5.36
Explanation:
Since this is a titration of a weak acid before reaching equivalence point, we will have effectively a buffer solution. Then we can use the Henderson-Hasselbalch equation to answer this question.
The reaction is:
HAc + NaOH ⇒ NaAc + H₂O
V NaOH = 40 mL x 1 L/1000 mL = 0.040 L
mol NaOH reacted with HAc = 0.040 L x 0.05 mol/L = 0.002 mol
mol HAC originally present = 0.050 L x 0.05 mol/L = 0.0025 mol
mol HAc left after reaction = 0.0025 - 0.002 = 0.0005
Now that we have calculated the quantities of the weak acid and its conjugate base in the buffer, we just plug the values into the equation
pH = pKa + log ((Ac⁻)/(HAc))
(Notice we do not have to calculate the molarities of Ac⁻ and HAc because the volumes cancel in the quotient)
pH = -log (1.75 x 10⁻⁵) + log (0.002/0.0005) = 5.36
THe answer is 5.36
Answer: The Answer is 18.7ml.
Explanation: Solved in the attached picture.
