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ElenaW [278]
3 years ago
14

Which of the following is ONE of the signs of a chemical change

Chemistry
2 answers:
Vlada [557]3 years ago
7 0
Which ONE please can you show the signs
pickupchik [31]3 years ago
6 0

Answer:

um i one of what?

Explanation:

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Grams of cl in 38g of cf3cl
Lerok [7]

Answer:

114 grams

Explanation:

3chlorines per compound*38grams=114

8 0
3 years ago
The gasses in a hair spray can are at temperature 300k and a pressure of 30 atm, it
Sergeeva-Olga [200]

Answer:

900 K

Explanation:

Recall the ideal gas law:

\displaystyle PV = nRT

Because only pressure and temperature is changing, we can rearrange the equation as follows:
\displaystyle \frac{P}{T} = \frac{nR}{V}

The right-hand side stays constant. Therefore:

\displaystyle \frac{P_1}{T_1} = \frac{P_2}{T_2}

The can explodes at a pressure of 90 atm. The current temperature and pressure is 300 K and 30 atm, respectively.

Substitute and solve for <em>T</em>₂:

\displaystyle \begin{aligned} \frac{(30\text{ atm})}{(300\text{ K})} & = \frac{(90\text{ atm})}{T_2} \\ \\ T_2 & = 900\text{ K}\end{aligned}

Hence, the temperature must be reach 900 K.

7 0
3 years ago
What are the different phases of matter and their characteristics?
Novay_Z [31]

Answer:

The five phases of matter. There are four natural states of matter: Solids, liquids, gases and plasma. The fifth state is the man-made Bose-Einstein condensates. In a solid, particles are packed tightly together so they don't move much.

3 0
3 years ago
Read 2 more answers
A sample of a compound contains 32.0 g C and 8.0 g H. Its molar mass is 30.0 g/mol. What is the compound’s molecular formula
Grace [21]
The compound's molecular formula is C2H6. This is obtained by:
  
            mass             moles               divided by smallest moles
C          32g         32/12 = 2.67                                 1
H           8g           8/1.01 = 7.92                        approx. 3

Next, divide both terms by the smallest number of moles, 2.67. This gives 1 and 3. So the empirical formula is CH3 which has a molar mass of 15g/mol. Given the molar mass of the molecular formula as 30g/mole, we can calculate the factor by which to multiply the subscripts of CH3.

X = molar mass of molecular formula / molar mass of empirical formula = 30/15
X=2

So (CH3)2 is C2H6.
3 0
3 years ago
Select all steps below that you followed to practice laboratory safety during the experiment. used tongs or a test tube holder t
uysha [10]

Explanation:

Steps followed to practice laboratory safety during the experiment are as follows.

  • Used tongs or a test tube holder to hold materials over the Bunsen burner flame.
  • Wore gloves and goggles.
  • Made careful observations of the products and reactants.
  • Did not smell the gases produced.

When we heat a test tube over bunsen flame then the tube gets hot and when we hold it with bare hands then out hands will burn. Therefore, it is advised to hold test tube with the help of tongs or a holder so that our hands did not burn.

We should also wear gloves and goggles so that any acid would not spill directly on our hands, skin and eyes as it can affect or damage the skin severely.

Careful observations were made so that correct calculations about the experiment can be carried out.

It is also advised that we should not smell the gases produced but gases move freely from one place to another in a laboratory or any where else.

So, we can try to avoid it by covering our mouth with a cloth but we cannot stop it. If we keep on inhaling the gases produced in a laboratory then it can also lead to severe disease or defect in the human body.

8 0
3 years ago
Read 2 more answers
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