answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
dimulka [17.4K]
2 years ago
8

Hydrogen gas and bromine gas react to form hydrogen bromide gas. How much heat (kJ) is released when 155 grams of HBr is formed

in this reaction? ΔH° = -72 kJ.
Chemistry
1 answer:
VashaNatasha [74]2 years ago
8 0

Answer:

-37.63KJ

Explanation:

First, we write an equation of reaction:

H + Br ——-> HBr

Now we are told that 155g of HBr is formed. We can calculate the number of moles of HBr formed as follows:

We simply divide the mass of the HBr formed by the molar mass of HBr. The molar mass of HBr is 81g/mol

The number of moles of HBr formed is thus 81/155 = 0.52 moles

The amount of heat released is thus 0.52 * (-72) = -37.63KJ

You might be interested in
Many enzymes are inhibited irreversibly by heavy metal ions such as Hg2+ , Cu2+ , or Ag+ , which can react with essential sulfhy
3241004551 [841]

Answer:

The minimum molecular weight of the enzyme is 29.82 g/mol

Explanation:

<u>Step 1:</u> Given data

The volume of the solution = 10 ml = 10*10^-3L

Molarity of the solution = 1.3 mg/ml

moles of AgNO3 added = 0.436 µmol = 0.436 * 10^-3 mmol

<u>Step 2:</u> Calculate the mass

Density = mass/ volume

1.3mg/mL = mass/ 10.0 mL

mass = 1.3mg/mL *10.0 mL = 13mg

<u>Step 3:</u> Calculate minimum molecular weight

Molecular weight = mass of the enzyme / number of moles

Molecular weight of the enzyme = 13mg/ 0.436 * 10^-3 mmol

Molecular weight = 29.82 g/mole

The minimum molecular weight of the enzyme is 29.82 g/mol

7 0
2 years ago
one method for generating chlorine gas is by reacting potassium permanganate and hydrochloric acid. how many liters of Cl2 at 40
Ronch [10]

<u>Answer:</u> The volume of chlorine gas produced in the reaction is 2.06 L.

<u>Explanation:</u>

  • <u>For potassium permanganate:</u>

To calculate the number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}

Given mass of potassium permanganate = 6.23 g

Molar mass of potassium permanganate = 158.034 g/mol

Putting values in above equation, we get:

\text{Moles of potassium permanganate}=\frac{6.23g}{158.034g/mol}=0.039mol

  • <u>For hydrochloric acid:</u>

To calculate the moles of hydrochloric acid, we use the equation:

\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}

Molarity of HCl = 6.00 M

Volume of HCl = 45.0 mL = 0.045 L   (Conversion factor: 1 L = 1000 mL)

Putting values in above equation, we get:

6.00mol/L=\frac{\text{Moles of HCl}}{0.045L}\\\\\text{Moles of HCl}=0.27mol

  • For the reaction of potassium permanganate and hydrochloric acid, the equation follows:

2KMnO_4+16HCl\rightarrow 2MnCl_2+5Cl_2+2KCl+8H_2O

By Stoichiometry of the reaction:

16 moles of hydrochloric acid reacts with 2 moles of potassium permanganate.

So, 0.27 moles of hydrochloric acid will react with = \frac{2}{16}\times 0.27=0.033moles of potassium permanganate.

As, given amount of potassium permanganate is more than the required amount. So, it is considered as an excess reagent.

Thus, hydrochloric acid is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

16 moles of hydrochloric acid reacts with 5 moles of chlorine gas.

So, 0.27 moles of hydrochloric acid will react with = \frac{5}{16}\times 0.27=0.0843moles of chlorine gas.

  • To calculate the volume of gas, we use the equation given by ideal gas equation:

PV=nRT

where,

P = pressure of the gas = 1.05 atm

V = Volume of gas = ? L

n = Number of moles = 0.0843 mol

R = Gas constant = 0.0820\text{ L atm }mol^{-1}K^{-1}

T = temperature of the gas = 40^oC=[40+273]K=313K

Putting values in above equation, we get:

1.05atm\times V=0.0843\times 0.0820\text{ L atm }mol^{-1}K^{-1}\times 313K\\\\V=2.06L

Hence, the volume of chlorine gas produced in the reaction is 2.06 L.

3 0
2 years ago
How many grams of caf2 would be needed to produce 8.41×10-1 moles of f2?
geniusboy [140]
Answer: 65.7 grams

Explanation:

1) ratio

Since 1 mole of CaF2 contains 1 mol of F2, the ratio is:

1 mol CaF2 : 1 mol F2

2) So, to produce 8.41 * 10^ -1` mol of F2 you need the same number of moles of CaF2.

3) use the formula:

mass in grams = molar mass * number of moles

molar mass of CaF2 = 40.1 g/mol + 2 * 19.0 g/mol = 78.1 g/mol

mass in grams = 78.1 g/mol * 8.41 * 10^ -1 mol = 65.7 grams
5 0
2 years ago
A 0.89% (w/v) sodium chloride solution is referred to as physiological saline solution because it has the same concentration of
maks197457 [2]
1) 0.89% m/v = 0.89 grams of NaCl / 100 ml of solution

=> 8.9 grams of NaCl in 1000 ml of solution = 8.9 grams of NaCl in 1 liter of solution

2) Molarity = M = number of moles of solute / liters of solution

=> calculate the number of moles of 8.9 grams of NaCl

3) molar mass of NaCl = 23.0 g /mol + 35.5 g/mol = 58.5 g / mol

4) number of moles of NaCl = mass / molar mass = 8.9 g / 58.5 g / mol = 0.152 mol

5) M = 0.152 mol NaCl / 1 liter solution = 0.152 M

Answer: 0.152 M
4 0
2 years ago
What is the molality of a solution in which 3.0 moles of NaCl is dissolved in 1.5 Kg of water?
Nesterboy [21]
Density H2O = 1g/cm³
1,5 kg H2O = 1500g = 1500cm³             (1dm³ = 1000cm³)

3moles of NaCl-----in---------1500cm³ H2O
x moles of NaCl ----in--------1000cm³ H2O
x = 2moles of NaCl

answer: 2 mol/dm³
5 0
2 years ago
Other questions:
  • Calculate the frequency of the n = 6 line in the Lyman series of hydrogen.
    15·2 answers
  • Draw the structure of (z)-3-methylhept-3-ene. be sure the stereochemistry is drawn clearly.
    7·1 answer
  • Current of 250. a flows for 24.0 hours at an anode where the reaction occurring is as follows: mn2+(aq) + 2h2o(l) → mno2(s) + 4h
    8·2 answers
  • What we call "tin cans" are really iron cans coated with a thin layer of tin. The anode is a bar of tin and the cathode is the i
    13·1 answer
  • The density of mercury is 13.6 g/cm3 . What volume (in quarts) is occupied by 100. g of Hg? (1 L = 1.06 qt)
    11·1 answer
  • Classify each of these soluble solutes as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. Solutes Formula Hydroch
    5·2 answers
  • Chose the statements that are TRUE from the list below Group of answer choices Ions exist alone in nature We add calcium carbona
    5·1 answer
  • Calculate the wavelength of a photon of green light that has a frequency (v) of 5.76x10^14 s^-1
    9·1 answer
  • Suppose you are titrating vinegar, which is an acetic acid solution of unknown strength, with a sodium hydroxide solution accord
    11·1 answer
  • A student obtained an unknown metal sample that weighed 65.3 g and at a temperature of 99.8oC, he placed it in a calorimeter con
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!