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3 years ago

True or false? dry ice subliming (turning from a solid straight into a gas) is an example of a chemical change.

1 answer:

5 0

False because when a substance changes from one state of matter to another it is a physical change no matter how many states of matter it skips

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In preparation for a blizzard, a city dispatches a crew to spread salt on the street surface of the bridges around town. The sal

timofeeve [1]

Solid to liquid because it wil defrost

4 0

3 years ago

If 500.0 mL of 0.10 M Ca2+ is mixed with 500.0 mL of 0.10 M SO42−, what mass of calcium sulfate will precipitate? Ksp for CaSO4

statuscvo [17]

Answer:

The mass of calcium sulfate that will precipitate is 6.14 grams

Explanation:

Step 1: Data given

500.0 mL of 0.10 M Ca^2+ is mixed with 500.0 mL of 0.10 M SO4^2−

Ksp for CaSO4 is 2.40*10^−5

Step 2: Calculate moles of Ca^2+

Moles of Ca^2+ = Molarity Ca^2+ * volume

Moles of Ca^2+ = 0.10 * 0.500 L

Moles Ca^2+ = 0.05 moles

Step 3: Calculate moles of SO4^2-

Moles of SO4^2- = 0.10 * 0.500 L

Moles SO4^2- = 0.05 moles

Step 4: Calculate total volume

500.0 mL + 500.0 mL = 1000 mL = 1L

Step 5: Calculate Q

Q = [Ca2+] [SO42-]

[Ca2+]= 0.050 M [O42-]

Qsp = (0.050)(0.050 )=0.0025 >> Ksp

This means precipitation will occur

Step 6: Calculate molar solubility

Ksp = 2.40 * 10^-5 = [Ca2+][SO42-] =(x)(x)

2.40 * 10^-5 = x²

x = √(2.40 * 10^-5)

x = 0.0049 M = Molar solubility

Step 7: Calculate total CaSO4 dissolved

total CaSO4 dissolved = 0.0049 M * 1 L * 136.14 mol/L = 0.667 g

Step 8: Calculate initial mass of CaSO4

Since initial moles CaSo4 = 0.050

Initial mass of CaSO4 = 0.050 * 136.14 g/mol

Initial mass of CaSO4 = 6.807 grams

Step 9: Calculate mass precipitate

6.807 - 0.667 = 6.14 grams

The mass of calcium sulfate that will precipitate is 6.14 grams

5 0

3 years ago

Ammonia is produced industrially via this exothermic reaction.

Cloud [144]

Answer:

high pressure of 200-300 atm.

low temp. of between 400-500 degrees celsius:this is for continuous development of ammonia since it decomposes at high temp fathermore the reaction is exothermic

a catalyst to speed up the rate of reaction:i guess it is finely divided iron impregnated in aluminium oxide

platinum can be used as a catalyst but it is easily poisoned

hope it helps

Explanation:

6 0

3 years ago

BRAINLIESTTT ASAP! PLEASE ANSWER IN YOUR OWN WORDS. :)

const2013 [10]

Answer:

The atomic structure of an atom involves 3 subatomic particles: the proton, neutron, and electron. The proton has a positive charge and is found in the core of the atom, with the neutral neutrons that also have a mass of 1 amu (atomic mass unit) just like the proton. The nucleus is the core of the atom and contains protons and neutrons and is practically the only area with mass. The electron cloud is basically an area surrounding the nucleus and it contains negative charged electrons. Electrons have no mass but are charged with a negative charge that keeps them. I really hope this helps :)

Explanation:

There is a helpful video that actually explains the structure of an atom in a rather fun way in just 2 minutes. It really does help big time and it's kinda funny if you look it up on YT and watch:

WKRP: Venus Explains the Atom

Have a wonderful great day :)

8 0

3 years ago

Which of the following undergoes change during a chemical reaction? A. atomic masses of elements in reactants B. element identit

Virty [35]

Chemical bonds between atoms in reactants undergo change during a chemical reaction.

The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants.

The correct answer between all the choices given is the last choice or letter D. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.

8 0

3 years ago