Answer:
2.1 x 10^24 Cr ions
Explanation:
You need to multiply the 3.5 mol by the Avogrado's number (6.022 x 10^23) to get your answer.
The reaction between NaOH and H₂SO₄ is as follows;
2NaOH + H₂SO₄ ---> Na₂SO₄ + 2H₂O
stoichiometry of base to acid is 2:1
NaOH is a strong acid and H₂SO₄ is a strong acid, therefore complete ionization into their respective ions takes place.
number of acid moles reacted - 0.112 M / 1000 mL/L x 39.1 mL = 0.0044 mol
the number of base moles required for neutralisation = 0.0044 x 2 = 0.0088 mol
Number of NaOH moles in 25.0 mL - 0.0088 mol
Therefore in 1000 mL - 0.0088 mol/ 25.0 mL x 1000 mL/L = 0.352 mol/L
Therefore molarity of NaOH - 0.352 M
Answer:
Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.
Explanation:
The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:
Time_________________ Amount
t=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/4
During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.
pH: 1.14266750357
pOH: 12.8573324964
[H+]: 0.072
[OH-]: 1.38888888889E-13 acid
The density of a solid object that has a mass of 1.62 lb and a volume of 190 mL is 3.87g/mL.
<h3>How to calculate density?</h3>
Density is the measure of the mass of matter contained by a unit volume. It can be calculated by dividing the mass of the substance by its volume.
According to this question, a solid object is said to have a mass of 1.62 lb and a volume of 190 mL.
1 pound = 453.592 grams
1.62 Ibs is equivalent to 734.82 grams
Density of the solid object = 734.82 grams ÷ 190 mL
Density = 3.87g/mL
Therefore, the density of a solid object that has a mass of 1.62 lb and a volume of 190 mL is 3.87g/mL.
Learn more density at: brainly.com/question/20337365
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