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3 years ago

Explain why a cool flame is important in heating a solution to dryness

1 answer:

5 0

Hot flames have a tendency to make problem and as the there is evaporation of solution it infrequently gets overheated and the fluid progresses toward becoming super heated. That regularly makes "bumping" in which the problem area ejects and that is probably going to scatter any solid and on the off chance that you are doing quantitative work that implies the trial is demolished and if not at least it will be a mess, that is why cool flames are important to use instead of hot flames.

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What causes the convection cell to turn downward

Leviafan [203]

Gravity when the mantle cools it becomes heavier and therfore sinks

4 0

4 years ago

Which of the following best describes the outcome of the cell division process meoisis?

mafiozo [28]

Answer:

Explanation: The answer is B. Because meiosis process produce genetically different, haploid cells. Also, meiosis basically happen to produce gametes. Gametes is haploid. So, the answer is B

6 0

3 years ago

Mass of water 50.003 g 24 95C Temperature of water Specific heat capacity for water 4.184J/g C Mass of metal 3.546 Temperature o

Norma-Jean [14]

Correct Question :

Mass of water = 50.003g

Temperature of water= 24.95C

Specific heat capacity for water = 4.184J/g C

Mass of metal = 63.546 g

Temperature of metal 99.95°C

Specific heat capacity for metal ?

Final temperature = 32.80°C

In an experiment to determine the specific heat of a metal student transferred a sample of the metal that was heated in boiling water into room temperature water in an insulated cup. The student recorded the temperature of the water after thermal equilibrium was reached. The data we shown in the table above. Based on the data, what is the calculated heat absorbed by the water reported with the appropriate number of significant figures?

Answer:

1642 J

Explanation:

Given:

Mass of water = 50.003g

Temperature of water= 24.95C

Specific heat capacity for water = 4.184J/g C

Mass of metal = 63.546 g

Temperature of metal 99.95°C

Specific heat capacity for metal ?

Final temperature = 32.80° C

To calculate the heat absorbed by water, Q, let's use the formula :

Q = ∆T * mass of water * specific heat

Where ∆T = 32.80°C - 24.95°C = 7.85°C

Therefore,

Q= 7.85 * 50.003 * 4.184

Q = 1642.32 J

≈ 1642 J

8 0

4 years ago

Watching the assignment without knowing how to solve the questions is the worst thing to experience hope someone can help with t

frez [133]

Answer:

- 622.5kJ

Explanation:

1) 2NH3 + 3N2O ----> 4N2 + 3H2O ΔH° 1= - 1010kJ

- 3 (N2O + 3H2 ---> N2H4 + H2O ΔH° 2 = - 317 kJ)

2) 2NH3 + 3N2O ----> 4N2 + 3H2O ΔH° 1= - 1010kJ

- 3N2O - 9 H2 ----> - 3N2H4 - 3H2O - 3ΔH° 2 = 3*317 kJ

2NH3 + 3N2H4 --->4N2+9H2, ΔH° 1 - 3*ΔH° 2

2NH3 + 3N2H4 --->4N2+9H2, ΔH° 1 - 3*ΔH° 2

3) -(2NH3 +1/2O2 ---> N2H4 + H2O, ΔH°3 = -143 kJ)

-2NH3 - 1/2O2 ---> - N2H4 - H2O, - ΔH°3 = 143 kJ

2NH3 + 3N2H4 --->4N2+9H2, ΔH° 1 - 3*ΔH° 2

-2NH3 - 1/2O2 ---> - N2H4 - H2O, - ΔH°3 = 143 kJ

4N2H4 + H2O ---> 4N2 + 9H2 + 1/2O2, ΔH° 1 - 3*ΔH° 2 - ΔH°3

H2 + 1/2O2 ---> H2O, ΔH° 4 = - 286 kJ

9*(H2 + 1/2O2 ---> H2O, ΔH° 4 = - 286 kJ)

9H2+ 9/2 O2 ---> 9H2O, 9*ΔH° 4 = 9*(- 286) kJ

4N2H4 + H2O ---> 4N2 + 9H2 + 1/2O2, ΔH° 1 - 3*ΔH° 2 - ΔH°3

9H2+ 9/2 O2 ---> 9H2O, 9*ΔH° 4 = 9*(- 286) kJ

4N2H4 +4O2 --->4N2+8H2O, ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4

1/4*(4N2H4 +4O2 --->4N2+8H2O, ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4

N2H4 +O2 --->N2+2H2O, 1/4( ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4)

N2H4 +O2 --->N2+2,

1/4( ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4)=

=1/4(-1010kJ - 3*(-317kJ) - (-143kJ) + 9*(-286kJ))= - 622.5 kJ

7 0

3 years ago

Please Help! Thank You

ra1l [238]

Answer:

oooooooooooooooooh i dont know this one

Explanation:

im confuzzled

6 0

3 years ago