Which statement best represents a hypothesis?

Sodium tripolyphosphate is used in detergents to make them effective in hard water. calculate the oxidation number of phosphorus

Fed [463]

Step 1:
Write molecular Formula,

Na₅P₃O₁₀
Step 2:
Assign Oxidation number to Na (which is +1) and O (which is -2), and X (unknown) for P.
(+1)₅ + (X)₃ + (-2)₁₀ = 0

Zero means overall charge on molecule is zero (Neutral).

Step 3:
Now solve for X,
(+5) + (X ÷ 3) + (-20) = 0

X ÷ 3 = -5 + 20

X ÷ 3 = +15

X = +15 ÷ 3

X = +5

Result:
Oxidation number of P is +5.

3 0

3 years ago

What is the mass of 61.9 L of oxygen gas collected at STP?

Tcecarenko [31]

Answer:

D. 44.2 g O₂

General Formulas and Concepts:
Gas Laws

STP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 K

Stoichiometry

Dimensional Analysis
Mole Ratio

Explanation:

Step 1: Define

Identify given.

61.9 L O₂ at STP

Step 2: Convert

We know that the oxygen gas is at STP. Therefore, we can set up and solve for how many moles of O₂ is present:

$\displaystyle 61.9 \ \text{L} \ \text{O}_2 \bigg( \frac{1 \ \text{mol} \ \text{O}_2}{22.4 \ \text{L} \ \text{O}_2} \bigg) = 2.76339 \ \text{mol} \ \text{O}_2$

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 moles to grams:

$\displaystyle 2.76339 \ \text{mol} \ \text{O}_2 \bigg( \frac{16.00 \ \text{g} \ \text{O}_2}{1 \ \text{mol} \ \text{O}_2} \bigg) = 44.2143 \ \text{g} \ \text{O}_2$

Now we deal with sig figs. From the original problem, we are given 3 significant figures. Round your answer to the exact same number of sig figs:

$\displaystyle 44.2143 \ \text{g} \ \text{O} \approx \boxed{ 44.2 \ \text{g} \ \text{O}_2 }$

∴ our answer is letter choice D.

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Topic: AP Chemistry

Unit: Stoichiometry

6 0

2 years ago

What is the density of an object with a volume of 11.24 L and a mass of 3.45 g ?

Tasya [4]

Answer:

0.306 g/L

Explanation:

D = M/V

D= 3.45 g/11.24 L

D= 0.306 g/L

5 0

3 years ago

¿

zvonat [6]

Answer:

Es Vendeis o puedes poner vendes

Explanation:

7 0

3 years ago

What two gases have a profound effect on the type of organisms that can live in an area and influences the regions carrying capa

Over [174]

Answer:

Oxygen and Carbon dioxide

Explanation:

Oxygen is required for respiration whereby energy is released from natural occurring nutrients accompanied by the release of water and carbon dioxide. carbon dioxideis also required by plants to photosynthesise.

Oxygen and carbon dioxide in the troposphere supports life as by enabling respiration in organisms and photosynthesise in plants can. Without oxygen in an environment, only life forms that live by anaerobic respiration will thrive. This affects a regions carrying capacity

3 0

3 years ago

Which statement best represents a hypothesis￼?

Which statement best represents a hypothesis?