Answer:
Approximately 39.7 kJ.
Assumptions: the specific heat capacity of water is
, the melting point of water is
, and that the boiling point of water is
.
Explanation:
It takes five steps to convert 13.0 grams of
ice to steam at
.
- Step one: heat the 13.0 gram of ice from
to
. The change in temperature would be
. - Step two: supply the heat of fusion to convert that 13.0 gram of ice to water.
- Step three: heat the 13.0 gram of water from
to
. The change in temperature would be
. - Step four: supply the heat of vaporization to convert that 13.0 gram of water to steam.
- Step five: heat the 13.0 gram of steam from
to
. The change in temperature would be
.
<h3>Energy required for step one, three, and five</h3>
The following equation gives the amount of energy
required to raise the temperature of an object by a
:
.
In this equation,
is the specific heat of this substance,
is the mass of the substance, and
is the change in the temperature of the object.
Assume that there's no mass loss in this whole process. The value of
would stay the same at
.
.
<h3>Energy required for step two and four</h3>
The equations for the energy of fusion and energy of vaporization are quite similar:
.
.
where
is the number of moles of the substance.
Look up the relative atomic mass of oxygen and hydrogen from a modern periodic table:
Hence the molar mass of water:
.
Number of moles of
molecules in
:
.

<h3>Energy required for all five steps, combined</h3>
.
Gina made 9{,}350 \text{ mL}9,350 mL9, comma, 350, space, m, L of chicken noodle soup. She packed 1.8 \text{ L}1.8 L1, point, 8,
RoseWind [281]
Answer:

Explanation:
Remember that

To convert L to mL multiply by 1,000
we know that
Gina made 9,350 mL
She packed 1.8 L of the soup in her kids' lunches
She froze the rest of the soup
step 1
Convert L to mL

step 2
To find out how many milliliters of soup did Gina have left to freeze, subtract 1,800 mL from 9,350 mL

Acetic acid, phosphoric acid, hydrochloric acid.
sodium bicarbonate, magnesium hydroxide, aluminum hydroxide
calcium carbonate, sodium bicarbonate, magnesium sulfate.
17) 8.4 / 20 x 100
18) 20 . 0.5150
19) 6,50% because (as you said) the law of definite proportions states that regardless of the amount, a compound is always composed of the same elements in the same proportion by mass
Answer: D : A is 3 : 2.
Explanation:
The law of definite proportion is being used here. The law states that a given compound always has the same proportion of its constituent elements by mass.
2a + b = c + 3d
This actually means that, two moles of “a” react with a mole of “b” to produce a mole of “c” and 3 moles of “d”
Using the concept of stoichiometry coefficients of d and a
d:a = 3:2