A mixture is always made up of a combination of elements

Answer:

Mn is the oxidizing agent.

N is the reducing agent.

Explanation:

Hello!

In this case, according to the undergoing chemical reaction, it is seen that the manganese in KMnO4 has an oxidation state of 7+, in MnSO4 of 2+ and nitrogen in KNO2 is 3+ and in KNO3 is 5+; thus we have the following half-reactions:

$Mn^{7+}+5e^-\rightarrow Mn^{2+}\\\\N^{3+}\rightarrow N^{5+}+2e^-$

Thus, since manganese is undergoing a decrease in the oxidation state, we infer it is the oxidizing agent whereas nitrogen, undergoing an increase in the oxidation state is the reducing agent.

Best regards!

5 0

3 years ago

The p-value of a statistical test depends on all of the following, except:

vaieri [72.5K]

Answer:

The correct option is e.

Explanation:

p-value is the probability value for a given statistical model, the probability that, when the null hypothesis is true.

For two two samples the formula of test statistics is

$t=\frac{(\overline{x}_1-\overline{x}_2)-(\mu_1-\mu_2)}{\sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2}}}$

where,

$\overline{x}$ is sample mean

$\mu$ is population mean.

$s$ is standard deviation.

n is sample size.

Variance is the square of standard deviation.

It means variance, mean, numbers of samples is used in calculation of p-value.

Degree of freedom define the shape of the t-distribution that your t-test uses to calculate the p-value.

$d.f.=n_1+n_2-2$

p-value of a statistical test depends on all of the following, except median.

Therefore the correct option is e.

4 0

3 years ago

Question 2 of 50

wolverine [178]

The thermal decomposition of calcium carbonate will produce 14 g of calcium oxide. The stoichiometric ratio of calcium carbonate to calcium oxide is 1:1, therefore the number of moles of calcium carbonate decomposed is equal to the number of moles of calcium oxide formed.

Further Explanation:

To solve this problem, follow the steps below:

Write the balanced chemical equation for the given reaction.
Convert the mass of calcium carbonate into moles.
Determine the number of moles of calcium oxide formed by using the stoichiometric ratio for calcium oxide and calcium carbonate based on the coefficient of the chemical equation.
Convert the number of moles of calcium oxide into mass.

Solving the given problem using the steps above:

STEP 1: The balanced chemical equation for the given reaction is:

$CaCO_{3} \rightarrow \ CaO \ + \ CO_{2}$

STEP 2: Convert the mass of calcium carbonate into moles using the molar mass of calcium carbonate.

$mol \ CaCO_{3} \ = 25 \ g \ CaCO_{3} \ (\frac{1 \ mol \ CaCO_{3}}{100.0869 \ g \ CaCO_{3}})\\ \\\boxed {mol \ CaCO_{3} \ = 0.2498 \ mol}$

STEP 3: Use the stoichiometric ratio to determine the number of moles of CaO formed.

For every mole of calcium carbonate decomposed, one more of a calcium oxide is formed. Therefore,

$mol \ CaO \ = 0.2498 \ mol$

STEP 4: Convert the moles of CaO into mass of CaO using its molar mass.

$mass \ CaO \ = 0.2498 \ mol \ CaO \ (\frac{56.0774 \ g \ CaO}{1 \ mol \ CaO})\\ \\mass \ CaO \ = 14.008 \ g$

Since there are only 2 significant figures in the given, the final answer must have the same number of significant figures.

Therefore,

$\boxed {mass \ CaO \ = 14 \ g}$

Learn More

Learn more about stoichiometry brainly.com/question/12979299
Learn more about mole conversion brainly.com/question/12972204
Learn more about limiting reactants brainly.com/question/12979491

Keywords: thermal decomposition, stoichiometry

5 0

3 years ago

Use the molar heat capacity for aluminum from table 1 to calculate the amount of energy needed to raise the temperature of 260.5

Nimfa-mama [501]

Unfortunately, you failed to include the table 1 from which the molar heat capacity of aluminum could have been obtained. However, as a general rule, the heat needed to raise the temperature of a certain substance by certain degrees is calculated through the equation,
H = mcpdT
where H is heat, m is mass, cp is specific heat capacity, and dT is change in temperature. From a reliable source, cp for aluminum is equal to 0.215 cal/g°C. Substituting this to the equation,
H = (260.5 g)(0.215 cal/g°C)(125°C - 0)
H = 7000.94 cal

6 0

3 years ago

Which of the following frequencies corresponds to light with the longest wavelength? A) 3.00 times 10^13 s^-1 B) 4.12 times 10^5

Vsevolod [243]

Answer:

1) B. 4.12 times 10^5 s^-1

2) B. frequency-v

3) C. 1.18 times 10^15 s^-1

4) B. 4.39 times 10^-19 J

5) B. Energy is absorbed

6) C. 3

7) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2

Explanation:

1)

The wavelength is inversely proportional to the frequency. Thus, the smallest frequency shall correspond to the longest wavelength. Thus, the correct answer is B. 4.12 times 10^5 s^-1

2)

B. frequency-v are wrongly paired because frequency is represented by f. Thus, correct pair will be frequency-f.

3)

The relationship between wavelength (λ) and frequency (f) is:

c = fλ

f = c/λ

where, c = speed of light = 3 x 10^8 m/s

f = (3x10^8 m/s) / (254 x 10^-9 m)

f = 1.18 x 10^15 s^-1

Thus, the correct option is C. 1.18 times 10^15 s^-1.

4)

The energy of photon is given as:

E = hc/λ

where, c = speed of light = 3 x 10^8 m/s

h = Plank's Constant = 6.625 x 10^-34 J.s

E = (6.625 x 10^-34 J.s)(3 x 10^8 m/s) / (453 x 10^-9 m)

E = 4.39 x 10^-19 J

Thus, the correct option is B. 4.39 times 10^-19 J.

5)

Since, the higher energy levels away from nucleus have higher energies. So, in order to move an electron from lower to higher or distant energy level, it must absorb energy from external source. So, the correct option is B. Energy is absorbed.

6)

The P-Sub-level has three orbitals, each having two electrons. Thus, P-Sub-Level accommodates total of 6 electrons. The correct option is C. 3

7)

The electronic configuration of barium atom is:

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2

8 0

3 years ago