1answer.
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
Nadusha1986 [10]
3 years ago
10

Which is the most important question for deciding if a chemical reaction has occurred

Chemistry
2 answers:
cluponka [151]3 years ago
6 0
A chemical reaction undergoes a chemical change so the question you should ask if a chemical reaction has occurred is "Did a chemical change happened?". Chemical change in a reaction happens when you see bubbles, when the reaction increases or decreases in temperature or a precipitate is formed.
anastassius [24]3 years ago
4 0

Answer:

the answer is Was there any heat energy given off?

Explanation:

You might be interested in
Cellular respiration involves the use of oxygencarbon dioxide and the release of carbon dioxideoxygen
Reil [10]
Cellular respiration can be thought of as the opposite of photosynthesis.  In cellular respiration oxygen is turned into carbon dioxide  while in photosynthesis carbon dioxide is tuned to oxygen.

I hope this helps. let me know in the comments if anything is unclear. 
3 0
3 years ago
Read 2 more answers
- a) write the formula unit of calcium fluoride.
8090 [49]

Answer:

hope this image is helpful for you

5 0
3 years ago
A solution is prepared by mixing 50.0 mL toluene (C6H5CH3 d=0.867 g/mL) with 125 mL Benzene (C6H6 d=0.874 g/mL). Assuming that t
Tatiana [17]

Answer:

mass % = 28.4%

mole fraction = 0.252

molality = 3.08 molal

molarity = 2.69 M

Explanation:

Step 1: Data given

Volume of toluene = 50.0 mL = 0.05 L

Density toluene = 0.867 g/mL

Molar mass toluene = 92.14 g/mol

Volume of benzene = 125 mL = 0.125 L

Density benzene = 0.874 g/mL

Molar mass benzene = 78.11 g/mol

Step 2: Calculate masses

Mass = density * volume

Mass toluene = 50.0 mL * 0.867 g/mL = 43.35 g

Mass benzene = 125 mL * 0.874 g/mL = 109.25 g

Step 3: Calculate number of moles

Moles = mass / molar mass

Moles toluene = 43.35 grams /92.14 g/mol = 0.470 5 moles

Moles benzene = 109.25 grams / 78.11 g/mol = 1.399 moles

Step 4: Calculate molarity of toluene

Molarity = moles / volume

Molarity toluene = 0.4705 moles / 0.175 L = 2.69 M

Step 5: Calculate mass % of toluene

Mass % = (43.35 grams / (43.35 + 109.25) )*100 % = 28.4 %

Step 6: Calculate mole fraction of toluene

Mole fraction toluene = Moles toluene / total number of moles

Mole fraction toluene = 0.4705 / (0.4705 + 1.399) = 0.252

Step 7: Molality of toluene

Molality = number of moles / mass

Molality of toluene = 0.4705 moles / (0.04335 + 0.10925)

Molality of toluene = 3.08 molal

4 0
3 years ago
If arranged in order of increasing atomic mass, which element would come after chlorine?
Eva8 [605]
Look at the periodic table the element next at the right of Cl is the Ar and the atomic mass is 39.948 is bigger than the Cl 35.45. All the elements after that has mases bigger than Cl.
3 0
3 years ago
Read 2 more answers
What is a synthesis reaction? a reaction that occurs when two or more reactants combine into one product
dmitriy555 [2]

Answer:

A synthesis reaction is <em>a reaction that occurs when two or more reactants combine into one product.</em>

Explanation:

A reaction that occurs when two or more reactants combine into one product is called a synthesis reaction.

A reaction that occurs when one element within a compound is exchanged with another element is called a single replacement reaction.

A reaction that occurs when a substance combines with molecular oxygen, releasing light and energy is called combustion.

A reaction that occurs when a single substance breaks apart and forms two or more new substances is called decomposition.

7 0
3 years ago
Other questions:
  • Nitrogen dioxide decomposes to nitric oxide and oxygen via the reaction: 2NO2 → 2NO + O2 In a particular experiment at 300 °C, [
    5·1 answer
  • Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of –7.2°C. Bromine can be classified as a
    6·2 answers
  • Compare and contrast the Bohr model of the atom with the modern model of the atom. What observations does the modern model expla
    5·2 answers
  • What happens to the Subatomic particles of an object when it is charged by induction?
    14·1 answer
  • The Uber fare in Seattle is $3.00 per mile. Evan took an Uber from Pike Place
    12·1 answer
  • When a calcium atom forms an ion, it loses two electrons. what is the eletrical charge ofbthe calcium ion?
    9·2 answers
  • If 52.5 mL of lead(II) nitrate solution reacts completely with excess sodium iodide solution to yield 0.248 g of precipitate, wh
    5·1 answer
  • How many moles of oxygen are required to react completely with 5.00 grams of hydrogen?
    13·1 answer
  • What would sunscreen look like if it absorbed all of the visible light that hit it?
    6·1 answer
  • Electrons are the most<br> important electrons to an atom. a) outer b) inner
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!