## Search found 170 matches

Fri Jul 23, 2021 9:13 am
Forum: Chemistry forum
Topic: Electron-transfer reaction
Replies: 1
Views: 33

### Electron-transfer reaction

1)What current will be required to produce 1.0 g of Na in 10.0 min. by electrolysis of molten NaCl? 2) What quantity of electricity will provide 0.624 mol of electrons? 3)If the current is 3.5 A, how many Coulombs per second are passing through the cell? 4) How many minutes will be required for a cu...
Fri Jul 09, 2021 2:36 am
Forum: Chemistry forum
Topic: Drawing chemical structure of C₂₈H₄₀O₇
Replies: 0
Views: 103

### Drawing chemical structure of C₂₈H₄₀O₇

How can i draw chemical structure of C28H40O7 Phorbol 12,13- Dibutanoate in ACD/Chemsketch ACD/Labs 2020.1.1 (file version C15E41 Build 115819)
Mon Jul 05, 2021 9:52 am
Forum: Chemistry forum
Topic: Computing mass of CaF₂
Replies: 3
Views: 146

### Re: Computing mass of CaF₂

Mass of the CaF2 is 0.0304718 moles × 78.1 g(molar mass of CaF2 = 2.38 g. I computed the solubility of CaF2 Calcium Fluoride in grams per liter in water from the Kₛₚ 3.5e-11 = 1.6 × 10⁻² g CaF2/L. Molar solubility of CaF2 in 0.07145 M of NaF solution is 4.89E-10 M. Are the above answers correct? How...
Mon Jul 05, 2021 1:25 am
Forum: Chemistry forum
Topic: Computing mass of CaF₂
Replies: 3
Views: 146

### Computing mass of CaF₂

Calculate the mass of CaF2 produced when 5g of Ca(NO3)2 is mixed with 3g of NaF in water, with a final volume of 500 mL. Ksp is 3.5E-11 for the system. My attempt to answer: Reaction equation is Ca(NO3)2 + 2NaF → CaF2 + 2NaNO3, we have 3.047e-2 moles of Calcium Nitrate and 7.145e-2 moles of Sodium F...
Sun Jul 04, 2021 8:38 pm
Forum: Chemistry forum
Topic: Enthalpy of reaction using one equation and its enthalpy
Replies: 2
Views: 150

### Re: Enthalpy of reaction using one equation and its enthalpy

For readers and viewers , detailed answer to this question is available at https://www.chemicalforums.com/index.php?topic=108524.0
Sat Jul 03, 2021 1:20 am
Forum: Chemistry forum
Topic: Enthalpy of reaction using one equation and its enthalpy
Replies: 2
Views: 150

### Enthalpy of reaction using one equation and its enthalpy

How much heat is produced when 100 mL of 0.250 M HCl (density, 1.00 g/mL) and 200 mL of 0.150 M NaOH (density, 1.00 g/mL) are mixed? HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l) ∆H°₂₅°c = −58 kJ If both solutions are at the same temperature and the heat capacity of the products is 4.19 J/g℃, how much will...
Thu Jul 01, 2021 3:11 am
Forum: Chemistry forum
Topic: Thermochemistry questions(1)
Replies: 5
Views: 216

### Re: Thermochemistry questions(1)

Initial temperature of iron was 100.0℃ and its final temperature is equal to final temperature of the system which is 23.59℃. So ∆T for 48.59 g sample of iron is 100.0℃- 23.59℃= 76.41℃. If you read carefully, you will notice that the questioner asked how much heat absorbed by coffee cup calorimeter,...
Wed Jun 30, 2021 10:49 pm
Forum: Chemistry forum
Topic: Thermochemistry questions(1)
Replies: 5
Views: 216

### Re: Thermochemistry questions(1)

This reaction released 1670.743 J of heat out of which 847.04 Jwas absorbed by coffee-cup calorimeter and 823.70 J was absorbed by water.
Wed Jun 30, 2021 5:27 am
Forum: Chemistry forum
Topic: Thermochemistry question part (2)
Replies: 3
Views: 147

### Re: Thermochemistry question part (2)

Both the reactions are endothermic , but your negative signs implies both reactions are exothermic. How is that?
Wed Jun 30, 2021 12:56 am
Forum: Chemistry forum
Topic: Balance chemical equation
Replies: 1
Views: 155

### Balance chemical equation

Given the following: Fe + CO2 → Fe2O3 + CO △ H°= + 25.0 kj

a) Give the balanced thermochemical equation.
2Fe(III)(s) + 3CO2 (g) → Fe2O3 (s) + 3CO (g)

b) Is this reaction exothermic or endothermic?
My answer: This reaction is endothermic.
Tue Jun 29, 2021 11:03 pm
Forum: Chemistry forum
Topic: Thermochemistry question part (2)
Replies: 3
Views: 147

### Thermochemistry question part (2)

1]Consider the following balanced reaction: 2A_2 + 3B \rightarrow C_2 + 2D What is the enthalpy of reaction if the enthalpy of formation of the compounds is given as A_2 = 7.78 kJ/mol; B = -18.43 kJ/mol; C_2 = 0 kJ/mol; D = 9.96 kJ/mol. Record your answer in scientific notation using 3 significant f...
Tue Jun 29, 2021 10:18 pm
Forum: Chemistry forum
Topic: Thermochemistry questions(1)
Replies: 5
Views: 216

### Thermochemistry questions(1)

A 48.59 gram sample of iron (with a heat capacity of 0.450 J/g ºC) is heated to 100.0 ºC. It is then transferred to a coffee cup calorimeter containing 66.51 g of water (specific heat of 4.184 J/ g ºC) initially at 20.63 ºC. If the final temperature of the system is 23.59 ºC, how much heat was absor...
Tue Jun 29, 2021 10:10 pm
Forum: Chemistry forum
Topic: Thermochemistry question
Replies: 3
Views: 132

### Re: Thermochemistry question

Correct answer provided is Heat capacity is Extensive property. But you said both a) and b) are correct. How is that?
Tue Jun 29, 2021 9:46 pm
Forum: Chemistry forum
Topic: Thermochemistry question
Replies: 3
Views: 132

### Thermochemistry question

1)A gold block has a mass of 0.630 kg and is initially at a temperature of 15.4℃. How much energy must be transferred to the block as heat for it to reach a final temperature of 49.3℃? Use c_{gold }=452 J/kg•K for the specific heat value of gold. a) 4,390 J b) 14,000 J c)-14,000 J d)-9,650 J e) 9,65...
Fri Jun 11, 2021 8:09 pm
Forum: Chemistry forum
Topic: Units of measurement of potential energy
Replies: 2
Views: 172