Answer:
<em>The correct option is B) a gradual change of the traits of a species over time</em>
Explanation:
The theory of natural selection explains the gradual changes which occur in the population of a species over time. According to natural selection, those organisms which are better adapted to live in an environment survive and pass on their traits to their offsprings. As a result, the traits of a species tend to change over time through the process of evolution. Evolutionary changes do not occur rapidly, instead, they can take many years to occur.
Molarity can be defined as the number of moles of substance dissolved in 1 L of solution.
In the given question ,
number of LiOH moles - 1.495 mol
Dissolved volume - 750 mL
molarity is calculated for 1 L = 1000 mL
In 750 mL - 1.495 mol of LiOH is dissolved
Therefore in 1000 mL - 1.495 mol / 750 mL x 1000 = 1.99 mol
Answer:
B. 1.65 L
Explanation:
Step 1: Write the balanced equation
2 SO₂(g) + O₂(g) ⇒ 2 SO₃(g)
Step 2: Calculate the moles of SO₂
The pressure of the gas is 1.20 atm and the temperature 25 °C (298 K). We can calculate the moles using the ideal gas equation.
P × V = n × R × T
n = P × V / R × T
n = 1.20 atm × 1.50 L / (0.0821 atm.L/mol.K) × 298 K = 0.0736 mol
Step 3: Calculate the moles of SO₃ produced
0.0736 mol SO₂ × 2 mol SO₃/2 mol SO₂ = 0.0736 mol SO₃
Step 4: Calculate the volume occupied by 0.0736 moles of SO₃ at STP
At STP, 1 mole of an ideal gas occupies 22.4 L.
0.0736 mol × 22.4 L/1 mol = 1.65 L
By crushing the salt, you are performing a physical change because you aren't altering the chemical makeup of the salt, just the physical form. Hope this helps! :)
<span>Which of the following is NOT true about "yield"? a. The value of the actual yield must be given in order for the percent yield to be calculated. b. The percent yield is the ratio of the actual yield to the theoretical yield. c. The actual yield may be different from the theoretical yield because reactions do not always go to completion. d. The actual yield may be different from the theoretical yield because insufficient limiting reagent was used.
The correct answer is:
</span><span> d. The actual yield may be different from the theoretical yield because insufficient limiting reagent was used.</span>
