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
Shalnov [3]
2 years ago
5

What describes a phase change

Chemistry
1 answer:
Finger [1]2 years ago
3 0
A phase change is when matter changes to from one state ( solid, liquid, gas, plasma) to another.
You might be interested in
How many moles of sodium bicarbonate are in 1.50 kg of the compound?
salantis [7]

Answer:

n=17.85 moles

Explanation:

Given mass is, m = 1.5 kg = 1500 g

The molar mass of sodium bicarbonate is, M = 84.007 g/mol

We need to find the no of moles in 1.5 kg of Sodium bicarbonate . We know that, no of moles is equal to given mass divided by molar mass.

n=\dfrac{m}{M}\\\\n=\dfrac{1500}{84.007 }\\\\n=17.85

<h2>So, there are 17.85 moles in 1.5 kg of Sodium bicarbonate.</h2>
3 0
3 years ago
Question 8 (9 points) <br><br>Match the lab equipment with its purpose
Deffense [45]

Answer:

\sf \boxed{4} \mapsto Pipet

\sf\boxed{7}\mapsto Test \:tube \: rack

\sf\boxed{3}\mapsto Test\: table

\sf\boxed{5}\mapsto Scoopula

\sf\boxed{1}\mapsto Graduated\: cylinder

\sf\boxed{9}\mapsto Bunsen \:burner

\sf\boxed{2}\mapsto Beaker

\sf \boxed{8}\mapsto Spot\: plate

\sf\boxed{6}\mapsto Goggles

Explanation:

Pipet is used to dispense a very small amount of liquid.

Test tube rack is used to hold multiple test tubes at the same time.

Test Table is used to view chemical reactions or hold or heat small amounts of substance.

Scoopula is used to dispense chemicals from a larger container.

Graduated cylinder is used to measure volume very precisely.

Bunsen burner is used to heat objects.

Beaker is used to transport heat or store substance.

Spot plate is used to observe the color changes of small quantities of a reacting mixture.

Goggles are used to protect the eyes from flying objects or chemical splashes.

_____________________________________________________

7 0
3 years ago
What volumes of 0.200 M HCOOH and 2.00 M NaOH would make 500. mL of a buffer with the same pH as a buffer made from 475 mL of 0.
Hitman42 [59]

Explanation:

The given data is as follows.

      [HCOOH] = 0.2 M,       [NaOH] = 2.0 M,

         V = 500 ml,   [Benzoic acid] = 0.2 M

First, we will calculate the number of moles of benzoic acid as follows.

   No. of moles of benzoic acid = Molarity × Volume

                         = 2 \times 0.475

                         = 0.095 mol

And, moles of NaOH present in the solution will be as follows.

    No. of moles of NaOH = Molarity × Volume

                          = 2 \times 0.025

                          = 0.05 mol

Hence, the ICE table for the chemical equation will be as follows.

         C_{6}H_{5}COOH + NaOH \rightarrow C_{6}H_{5}COONa + H_{2}O

Initial:        0.095           0.05            0             0

Equlbm:  (0.095 - 0.05)  0            0.05

        pH = pK_{a} + log \frac{Base}{Acid}  

              = 4.2 + log \frac{0.05}{0.045}

              = 4.245

For,  

         HCOOH + NaOH \rightarrow HCOONa + H_{2}O

Initial:       0.2x     2(0.5 - x)               0

Equlbm:   0.2x - 2(0.5 - x)                 0             2(0.5 - x)

As,

           pH = pK_{a} + log \frac{Base}{Acid}  

          4.245 = 3.75 + log \frac{Base}{Acid}

      log \frac{Base}{Acid} = 0.5

    \frac{Base}{Acid} = 3.162

Now,

        \frac{2(0.5 - x)}{0.2x - 2(0.5 - x)} = 3.162

               x = 0.464 L

Volume of NaOH = (0.5 - 0.464) L

                             = 0.036 L

                             = 36 ml               (as 1 L = 1000 mL)

And, volume of formic acid is 464 mL.

                 

8 0
3 years ago
The part of the flower responsible for producing pollen (sperm) is the _______.
IgorC [24]
Hello,

Here is your answer:

The proper answer to this question is option C "stigma".

Here is how:

The stigma is responsible for producing pollen in a plant.

Your answer is C.

If you need anymore help feel free to ask me!

Hope this helps!
7 0
3 years ago
Consider the car driving around a circular track .Once stated,the driver maintains a speed 0f 45m/h.Compare the driver's velocit
Lyrx [107]
A i hope that helped i love you guys have a great day
And merry chrismas

6 0
4 years ago
Other questions:
  • How many significant digits are in the length measurement 10.01 meters?
    13·1 answer
  • The titration of 25.0 ml of an iron(ii) solution required 18.0 ml of a 0.205 m solution of dichromate to reach the equivalence p
    9·1 answer
  • If two poisonous elements are combined chemically, which of the following will be true of the resulting compound?
    14·2 answers
  • Please HELPPPPP ME ASAP!​
    10·1 answer
  • When compounds form, which of the following statements is true about the elements that form them?
    7·1 answer
  • How do you know that a carrot is NOT a fruit?
    7·2 answers
  • In the following structure, carbons (I),(2),(3) and (4) are classified respectively as
    8·1 answer
  • URGENT ! PLEASE ANSWER QUICKLY
    12·2 answers
  • What is the density of a 500g box whose volume is 67 ml?
    15·1 answer
  • Give two reasons why a luminous flame is not used for heating purposes. (2mks) a​
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!