Answer:
D. 44.2 g O₂
General Formulas and Concepts:
<u>Gas Laws</u>
- STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at <em>1 atm, 273 K</em>
<u>Stoichiometry</u>
- Dimensional Analysis
- Mole Ratio
Explanation:
<u>Step 1: Define</u>
<em>Identify given.</em>
61.9 L O₂ at STP
<u>Step 2: Convert</u>
We know that the oxygen gas is at STP. Therefore, we can set up and solve for how many <em>moles</em> of O₂ is present:
Recall the Periodic Table (Refer to attachments). Oxygen's atomic mass is roughly 16.00 grams per mole (g/mol). We can use a mole ratio to convert from <em>moles</em> to <em>grams</em>:
Now we deal with sig figs. From the original problem, we are given 3 significant figures. Round your answer to the <u>exact</u> same number of sig figs:
∴ our answer is letter choice D.
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Topic: AP Chemistry
Unit: Stoichiometry
Answer: B- Isotopes are often used for dating artifacts and fossils is incorrect.
Explanation: I hope that helped
Answer:
See explanation
Explanation:
Let us look at the reaction again;
Cr2O7 2- (aq) + H2O(l)⇄ 2CrO4 2-(aq) + 2H^+(aq)
When we add sodium hydroxide to the system as shown, the hydroxide ion removes the hydrogen ion thereby leaving a large concentration CrO4^2-(aq) in the system this causes the solution to turn green(equilibrium position shifts to the right).
The net ionic equation is;
OH^-(aq) + H^+(aq) ----> H2O(l)
The reaction;
OH^-(aq) + H^+(aq) ----> H2O(l) is exothermic hence, if the temperature of the system is increased, the equilibrium position will shift towards the left hand side and the solution turns orange.
About 0.92 kg of benzyl salicylate would be needed in order to manufacture 325 tubes of sunscreen.
A tube contains 4.0 oz of the sunscreen and each one 2.5% benzyl salicylate.
2.5% of 4.0 oz = 0.1 oz
Thus, each tube would need 0.1 oz of benzyl salicylate.
325 tubes of the sunscreen is needed and each one requires 0.1 oz of benzyl salicylate. Hence, total amount of benzyl salicylate needed would be:
325 x 0.1 oz = 32.5 oz
From conversion:
16 oz = 1 lb
Hence,
32.5 oz = 32.5/16
= 2.03 lb
Also:
2.205 lb = 1 kg
2.03 lb = 2.03/2.205
= 0.92 kg
More on dimensional analysis can be found here: brainly.com/question/22015862
