Please help!!! Is it balanced or unbalanced?

Consider the reaction below. 2K+Br2------>2K+ +2Br-

sergeinik [125]

Answer: only Br2.

Justification.

In a chemical reaction the element that gains electrons experiments a reduction in its oxidation state, that is why it is said that it is reduced.

So, to know what element is being reduced you need to calculate the oxidation states of the elements involved.

Here I indicate the oxidation states of each element if the reaction putting them inside parenthesis:

Reactants side          Products side

K (0) K (1+)

Br (0)                          Br(1-)

So, K lost one electron, increasing its oxidation statefrom 0 to 1+, meaning that it is being oxidized.

And, each atom of Br gained one electron, reducing its oxidation state from 0 to 1-, meaning it is being reduced.

Therefore, the answer is that Br2 is the substance being reduced.

3 0

4 years ago

Read 2 more answers

When ammonia is mixed with hydrogen chloride (HCl), the white solid ammonium chloride (NH4Cl) is produced. Suppose 10.0 g ammoni

Alex_Xolod [135]

Answer:

There will remain 5.33 grams of NH3 and there will be produced 14.66 grams NH4Cl

Explanation:

Step 1: Data given

Mass of ammonia = 10.0 grams

Mass of hydrogen chloride = 10.0 grams

Molar mass of ammonia = 17.03 g/mol

Molar mass of hydrogen chloride = 36.46 g/mol

Step 2: the balanced equation

NH3 + HCl → NH4Cl

Step 3: Calculate moles NH3

Moles NH3 = mass NH3 / molar mass NH3

Moles NH3 = 10.0 grams / 17.03 g/mol

Moles NH3 = 0.587 moles

Step 4: Calculate moles HCl

Moles HCl = 10.0 grams / 36.46 g/mol

Moles HCl = 0.274 moles

Step 5: Calculate limiting reactant

For 1 mol NH3 we need 1 mol HCl to produce 1 mol NH4Cl

HCl is the limiting reactant. It will completely be consumed. (0.274 moles)

NH3 is in excess. There will remain 0.587 - 0.274 = 0.313 moles

This is: 0.313 moles * 17.03 = 5.33 grams

Step 6: Calculate moles NH4Cl

For 1 mol NH3 we need 1 mol HCl to produce 1 mol NH4Cl

For 0.274 moles HCl we need 0.274 moles NH4Cl

Step 7: Calculate mass of NH4Cl

Mass NH4Cl = moles NH4Cl * molar mass NH4Cl

Mass NH4Cl = 0.274 moles * 53.49 g/mol

Mass NH4Cl = 14.66 grams

There will remain 5.33 grams of NH3 and there will be produced 14.66 grams NH4Cl

4 0

4 years ago

A gas has a solubility of 2.45 g/L at a pressure of 0.750 atm. What pressure wold be required to produce an aqueous solution con

Lelechka [254]

Answer:

1.91 atm

Explanation:

Step 1: Calculate Henry's constant (k)

A gas has a solubility (C) of 2.45 g/L at a pressure (P) of 0.750 atm. These two variables are related to each other through Henry's law.

C = k × P

K = C/P

K = (2.45 g/L)/0.750 atm = 3.27 g/L.atm

Step 2: Calculate the pressure required to produce an aqueous solution containing 6.25 g/L of this gas at constant temperature.

We have C = 6.25 g/L and k = 3.27 g/L.atm. The required pressure is:

C = k × P

P = C/k

P = (6.25 g/L)/(3.27 g/L.atm) = 1.91 atm

3 0

3 years ago

Which of these is an example of physical change?

lana [24]

A. Boiling water is an example of physical change, whereas digesting food, breaking glass, and shoveling snow are not.

6 0

3 years ago

what is the molar mass of nicotine (C10H14N2)? Question 6 options: 14.11 g/mol 28.02 g/mol C 120.1 g/mol 162.2 g/mol C

viva [34]

Answer:

162.2 g/mol

Explanation:

Molar mass is defined as the mass in 1 mole of the substance. It is calculated by adding the molar mass of the substituents each multiplied by the subscript they have in the formula.

Thus, To calculate molar mass of nicotine having formula, $C_{10}H_{14}N_2$

Molar mass of C = 12.0107 g/mol

Molar mass of H = 1.00784 g/mol

Molar mass of N = 14.0067 g/mol

Thus, molar mass of nicotine = $12.0107\times 10+1.00784\times 14+14.0067\times 2$ = 162.2 g/mol

6 0

4 years ago