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
Hatshy [7]
3 years ago
9

When heating a flammable or volatile solvent for a recrystallization, which of these statements are correct? More than one answe

r may be correct.
a. You should not use an open flame to heat the solvent.
b. You should heat the solvent in a stoppered flask to keep vapor away from any open flames.
c. You should ensure that no one else is using an open flame near your experiment.
Chemistry
2 answers:
Citrus2011 [14]3 years ago
6 0

Answer:

You should not use an open flame to heat the solvent and the solvent should be heat in a stoppered flask to vapour away from the open flame

Explanation:

ruslelena [56]3 years ago
4 0

Answer:

A

Explanation:

You might be interested in
How many carbon atoms are present in 3.900 x 10-4 mol of carbon? Give your answer in scientific notation. x 10 (select) A
AnnyKZ [126]

<u>Answer:</u> The number of atoms of carbon present in given number of moles are 2.350\times 10^{20}

<u>Explanation:</u>

We are given:

Number of moles of carbon = 3.900\times 10^{-4}mol

According to mole concept:

1 mole of an element contains 6.022\times 10^{23} number of atoms.

So, 3.900\times 10^{-4}mol of carbon will contain = 3.900\times 10^{-4}\times 6.022\times 10^{23}=2.350\times 10^{20} number of atoms.

Hence, the number of atoms of carbon present in given number of moles are 2.350\times 10^{20}

4 0
3 years ago
An interesting enzyme, whose molecular weight is 56,000 g/mol, is used in catalytic amounts to cleave a membrane protein, whose
Anastaziya [24]

Answer:

65,000 g/mol,  43,000g/mol and 22,000 g/mol.

Explanation:

The explanation can be found in the attachment

4 0
3 years ago
Butter has a specific gravity of 0.86. What is the mass of 2.45 L<br> of butter?
Tema [17]

Answer:

mass of the butter is 2.107 kg

Explanation:

specific gravity = destiny of the substance / density of

the water at 4°C

0.86 = density of the butter / 1000

where density of the water is 1000 kg/m^3 at 4°C

density of the butter = 860kg/m^3

now,

density of the butter = mass of the butter / volume

860 = mass of the butter / 2.45 × 10^-3

( 1 L = 10^ -3 m^3)

mass of the butter = 2.107 kg

can I get brainlist plz

7 0
3 years ago
1. The following are statements about flames some of them are true while others are
hoa [83]

Answer:

i)The carbon particles are formed when the gas is not completely burnt(True)

ii)A solid or liquid must be change to gaseous state in order to make flame(TRUE)

iii)A non- luminous Bunsen flame produces has three visible regions(FALSE)

iv)The luminous Bunsen flame produces less soot than the non- luminous flame(FALSE)

v)A yellow Bunsen flame is obtained when the air holes are opened(FALSE)

vi)The luminous Bunsen flame is hotter than a non- luminous Bunsen flame(FALSE)

vii)Bunsen burner uses kerosene as a source of heat(FALSE)

Explanation:

i)When the incomplete combustion ,then CO(carbon monoxide) and C(carbon) are produced. <u>The unburnt carbon get deposited as</u><u> Soot</u>.

In complete combustion CO2(carbon dioxide) is produced.

ii)Fire, is the mixture of hot gases.Flame are result of chemical reaction between oxygen and fuel(e.g butane ,wood).Flame contain,carbon dioxide , heat ,light,steam.

iii)There are total three regions of flame in which the outer most region is the non-luminous .The non-luminous part is <u>blue(one visible region</u>) and does not emit-light.

iv) Luminous Bunsen flame produces more soot than the non- luminous flame because luminous flame contain more unburnt particles as compare to non-luminous.

luminous part has less oxygen available for complete combustion of fuel

v)When the air hole is open it means excess oxygen is supplied to the fuel.

In this case clean and luminous flame is produced.When air hole is close yellow flame is produced.

vi)Non-luminous part of flame is more hot because of complete combustion due to proper availability  of oxygen. Sometime the particle of non-luminous flame get ionize also.

vii).The bunsen burner uses Natural gas(methane) or LPG(propane and butane)as sources of heat because these are easily burnt not kerosene.

4 0
3 years ago
Describe a procedure to separate a mixture of sugar black pepper and pebbles
andreyandreev [35.5K]
1st you pour the mixture<span> through a filter to remove the larger </span>pebbles<span>. Next, add water to dissolve the salt and then filter out the </span>pepper the last thing you do <span>evaporate the water to leave the salt behind.</span>
5 0
3 years ago
Other questions:
  • At what temperature is the average speed of oxygen molecules equal to 1.12×104m/s?
    15·1 answer
  • Calculate the amount of energy that is absorbed by 75 g.. water
    11·1 answer
  • How does weathering affect the surface area of a rock? Explain your answer.
    10·1 answer
  • Magnesium has three naturally occurring isotopes with masses of 23.99 amuamu, 24.99 amuamu, and 25.98 amuamu and natural abundan
    12·2 answers
  • Given the formula for a compound:
    12·1 answer
  • Write a chemical equation representing the second ionization energy for lithium.
    15·2 answers
  • HCI
    6·2 answers
  • Is backbonding is possible in BF4- ? If no then why?
    8·1 answer
  • Which of the following definitions best fits the definition of an environmental factor of an organism's
    7·1 answer
  • Examples of symmetrical objects
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!