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3 years ago

What reaction illustrates the law of conservation of mass ?

1 answer:

8 0

The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. For example, when wood burns, the mass of the soot, ashes, and gases, equals the original mass of the charcoal and the oxygen when it first reacted. So the mass of the product equals the mass of the reactant

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How many grams of XeF6 are required to react with 0.579 L of hydrogen gas at 6.46 atm and 45°C in the reaction shown below?

ankoles [38]

The chemical reaction equation for this is

XeF6 + 3H2 ---> Xe + 6HF

Assuming gas behaves ideally, we use the ideal gas formula to solve for number of moles H2 with T = 318.15K (45C), P = 6.46 atm, V = 0.579L. Then we use the gas constant R = 0.08206 L atm K-1 mol-1.

we get n = 0.1433 moles H2

to get the mass of XeF6,

we divide 0.1433 moles H2 by 3 since 1 mole XeF6 needs 3 moles H2 to react then multiply by the molecular weight of XeF6 which is 245.28 g/mole XeF6.

0.1433 moles H2 x $\frac{1 mole XeF6}{3 moles H2}$ x $\frac{245.28 g XeF6}{1 mole XeF6}$ = 11.71 g XeF6

Therefore, 11.71 g of XeF6 is needed to completely react with 0.579 L of Hydrogen gas at 45 degrees Celcius and 6.46 atm.

3 0

3 years ago

Calculate the mass of liquid with density of 3.3 g/mL and a volume of 25 oz

love history [14]

Answer: 215

Explanation:

Volume doesn’t add up into ounces that’s mass only

3 0

3 years ago

The rate law for 2NO(g) + O₂(g) → 2NO₂(g) is rate = is rate k[NO]²[O₂]. is rateIn addition to the mechanism in the text (p. 709)

KonstantinChe [14]

The rate law depicts the effect of concentration on reaction rate. Second mechanism 2NO(g) ⇄ N₂O₂(g) [fast], N₂O₂(g) + O₂(g) → 2NO₂(g) [slow] is most reasonable. Thus, option b is correct.

Rate law and equation give the rate at which the reaction takes place under the influence of the concentration of the reactants. The balanced chemical reaction is given as,

2NO(g) + O₂(g) → 2NO₂(g)

The rate of the equation is given as,

rate = k [NO]² [O₂]

In a multi-step chemical reaction, the slowest step is the rate-determining step. The second mechanism is given as,

2NO (g) → N₂O₂ (g) [fast]

N₂O₂(g) +O₂(g) → 2NO₂ (g) [slow]

Rate is given as,

rate = k [N₂O₂] [O₂]

Therefore, option b. the second mechanism is the most reasonable.

Learn more about rate law, here:

brainly.com/question/14779101

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5 0

2 years ago

Night visin cameras are sensitive to energies around 2.21 x 10-19 J. What wavelength of electromagnetic radiation do they use?

defon

Answer:

8.99×10^-7m

Explanation:

The wavelength can be calculated using the expression below

E=hcλ

Where E= energy= 2.21 x 10^-19 J.

C= speed of light= 3x10^8 m/s

h= planks constant= 6.626 × 10^-34 m2 kg / s

E=hcλ

λ= E/(hc)

Substitute for the values

λ=( 2.21 x 10^-19 )/(6.626 × 10^-34 × 3x10^8 )

= 8.99×10^-7m

6 0

3 years ago

A buffer contains 0.18 mol of propionic acid (C2H5COOH) and 0.26 mol of sodium propionate (C2H5COONa) in 1.20 L. What is the pH

Yuki888 [10]

Answer:

1) pH = 5.05

2) pH = 5.13

3) pH = 4.97

Explanation:

Step 1: Data given

Number of moles of propionic acid = 0.18 moles

Number of moles sodium propionate = 0.26 moles

Volume = 1.20 L

Ka = 1.3 * 10^-5 → pKa = 4.989

Step 2: Calculate concentrations

Concentration = moles / volume

[acid]= 0.18/ 1.2 =0.150 M

[salt]= 0.26/ 1.3 = 0.217 M

pH = 4.89 + log(0.217/0.150)=<u>5.05</u>

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What is the pH of the buffer after the addition of 0.02 mol of NaOH?

moles acid = 0.18 - 0.02 = 0.16

[acid]= 0.16/ 1.2=0.133 M

moles salt = 0.26 + 0.02 = 0.28

[salt]= 0.28/ 12=0.233

pH = 4.89 + log 0.233/ 0.133 = 5.13

What is the pH of the buffer after the addition of 0.02 mol of HI?

moles acid = 0.18+ 0.02 = 0.20 moles

[acid]= 0.20/ 1.2 = 0.167 M

[salt]= 0.26 - 0.02= 0.24 moles

[salt]= 0.24/ 1.2 = 0.20 M

pH = 4.89 + log 0.20/ 0.167= 4.97

8 0

2 years ago