in the reaction 2na 2h2o 2naoh h2 what is the limiting reactant when 3 moles of sodium react with 2 moles of water

ATI TEAS 7

TEAS 7 science quizlet

1. In the reaction 2Na + 2H2O → 2NaOH + H2, what is the limiting reactant when 3 moles of sodium react with 2 moles of water?

A. Na
B. H2O
C. NaOH
D. H2

Correct answer: A

Rationale: The balanced chemical equation indicates that 2 moles of sodium react with 2 moles of water to yield 2 moles of sodium hydroxide and 1 mole of hydrogen gas. When 3 moles of sodium react with only 2 moles of water, sodium becomes the limiting reactant as it is present in excess compared to the available water molecules. This situation arises because not all sodium atoms can fully react with the limited amount of water, resulting in sodium being the limiting reactant in this specific case. Choice B (H2O), choice C (NaOH), and choice D (H2) are incorrect as they are not the limiting reactant in the given reaction scenario.

2. What is 0.025 mg converted to micrograms?

A. 25 mcg
B. 250 mcg
C. 2.5 mcg
D. 0.25 mcg

Correct answer: A

Rationale: To convert milligrams to micrograms, you need to multiply by 1000, not 10000. Therefore, 0.025 mg is equal to 25 mcg. The correct conversion is obtained by recognizing that 1 milligram (mg) is equal to 1000 micrograms (mcg). Choices B, C, and D are incorrect because they do not correctly convert milligrams to micrograms. Choice B is 10 times the correct answer, choice C is 100 times less, and choice D is 100 times less than the correct conversion.

3. Simplify the expression. Which of the following is the value of x? (5(4x – 5) = (3/2)(2x – 6))

A. −(2/7)
B. −(4/17)
C. (16/17)
D. (8/7)

Correct answer: C

Rationale: To solve the given proportion 5(4x – 5) = (3/2)(2x – 6), first distribute to get 20x - 25 = 3x - 9. Then, simplify the linear equation by isolating x: 20x - 3x = 25 - 9, which leads to 17x = 16. Finally, solving for x gives x = 16/17. Choice A is incorrect as it does not match the calculated value of x. Choice B is incorrect as it does not correspond to the correct solution for x. Choice D is incorrect as it does not align with the accurate value of x obtained from solving the equation.

4. What is 0.2 liters when converted to milliliters?

A. 20 ml
B. 200 ml
C. 2 ml
D. 2000 ml

Correct answer: B

Rationale: To convert liters to milliliters, you need to multiply by 1000, not 10000. Therefore, 0.2 liters equals 200 ml (0.2 x 1000 = 200 ml). Choice A, 20 ml, is incorrect because it's the result of multiplying by 10 instead of 1000. Choice C, 2 ml, is incorrect as it's the result of ignoring the decimal point. Choice D, 2000 ml, is incorrect because it's the result of multiplying by 10000.

5. Based on the contextual usage of this word, what is the most likely meaning of the prefix ante-?

A. again
B. good
C. before
D. together

Correct answer: C

Rationale: The prefix 'ante-' is commonly used to refer to something that comes before something else in terms of time, order, or position. In the provided sentence, the antechamber is described as a waiting area 'before' guests were allowed into the main hall. This usage indicates that 'ante-' in this context means 'before.' The other choices are incorrect: 'again' implies repetition, 'good' is unrelated, and 'together' does not fit the context of preceding or coming before something else.