![24swimdylanoh](/avatars/10732.jpg)
24swimdylanoh
18.12.2019 •
Chemistry
The standard enthalpy of reaction for the dissolution of silica in aqueous hf is 4.6 kj mol–1 . what is the standard enthalpy of formation of sif4(g)?
sio2(s) + 4 hf(aq) → sif4(g) + 2 h2o(l) ∆hºrxn = 4.6 kj mol–1
compound sio2(s) hf(aq) h2o(l) sif4(g)
∆hºf, kj mol–1 –910.9 –320.1 –285.8
(a) –1624.3 kj mol^–1
(b) –1615.1 kj mol^–1
(c) –949.8 kj mol^–1
(d) –940.6 kj mol^–1
Solved
Show answers
More tips
- W Work and Career Where can you learn to be a flight attendant?...
- C Cities and Countries What time does the Metro open in Moscow?...
- S Style and Beauty How to Get Rid of Under Eye Bruises?...
- F Food and Cooking How to Calculate the Gender of Your Child with Blood?...
- C Computers and Internet IMHO: What is it, why is it important, and how to use it?...
- H Health and Medicine Effective Ways to Treat Colic in Infants...
- H Health and Medicine How to Treat the Flu: A Comprehensive Guide...
- S Style and Beauty 5 Tips for Choosing the Best Ugg Boots...
- C Computers and Internet How to Create a Folder on Your iPhone?...
- C Computers and Internet iPhone SMS Delivery Report: How to Set It Up...
Answers on questions: Chemistry
- C Chemistry I am used for ceramics, I have cleavage and is very soft (hardness 1)...
- C Chemistry Trump and his fans r c r a z y...
- C Chemistry Write the net ionic equation between iron and copper (ii) sulfate....
- C Chemistry What is the name of the society that scientist form to bring about use one universal system of measurements? ( hurry)...
- C Chemistry Avertical feeding pattern is the amount of food predators eat a separation of animal habitats a way for animals to avoid competition the time of day animals eat...
- C Chemistry Ascientist wants to know if adults prefer watching movies in a theater or in their home. he interviews 500 people leaving a local movie theater and finds that 480 of them like watching...
- C Chemistry Look at this graph depicting the position of a person walking. during which interval was the person stationary?...
- C Chemistry HELPP PLEASEE this is science btw!!...
- M Mathematics A parallelogram has vertices (-3,2), (0,7), (7,7), and (x, 2). What is the value of x?...
- M Mathematics Each cude inside the rectangular prism has an edge length of 3/4 inch. what is the volume of the rectangle prism?...
Ответ:
B) ) –1615.1 kJ mol^–1
Explanation:
since
SiO2(s) + 4 HF(aq) → SiF4(g) + 2 H2O(l) ∆Hºrxn = 4.6 kJ mol–1
the enhalpy of reaction will be
∆Hºrxn = ∑νp*∆Hºfp - ∑νr*∆Hºfr
where ∆Hºrxn= enthalpy of reaction , ∆Hºfp= standard enthalpy of formation of products , ∆Hºfr = standard enthalpy of formation of reactants , νp=stoichiometric coffficient of products, νr=stoichiometric coffficient of reactants
therefore
∆Hºrxn = ∑νp*∆Hºfp - ∑νr*∆Hºfr
4.6 kJ/mol = [1*∆HºfX + 2*(–285.8 kJ/mol)] - [1*(–910.9kJ/mol) + 4*(–320.1 kJ/mol)]
4.6 kJ/mol =∆HºfX -571.6 kJ/mol + 2191.3 kJ/mol
∆HºfX = 4.6 kJ/mol + 571.6 kJ/mol - 2191.3 kJ/mol = -1615.1 kJ/mol
therefore ∆HºfX (unknown standard enthalpy of formation = standard enthalpy of formation of SiF4(g) ) = -1615.1 kJ/mol
Ответ:
answer:
okay.
explanation:
traffic signals are now controlled by programmable logic controllers. a plc is a limited-purpose, low-power computer that monitors an input circuit, and controls the output based on the value of the input.