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3 years ago

How much heat energy is required to raise the temperature of 20 kilograms of water from 0°C to 35°C?

Chemistry

1 answer:

alexgriva [62]3 years ago

7 0

The heat energy needed is 2928800J. Mass is given as 20 (kg)

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What is the exact mass of one mole of carbon-12 atoms

love history [14]

One atom of carbon weighs exactly 12/6.022x10^23 = 1.9927x10^-23 grams<span>.</span>

3 0

3 years ago

Determine the approximate amount of potassium hydrogen phthalate, KHP, that you will need to neutralize 6.00 ml of 0.100 M NaOH.

Sveta_85 [38]

Answer:

potassium hydrogen phthalate KHP MOLAR MASS = 204.233 glmol

to get 1000 ml

Molar concentration = Mass concentration/Molar Mass

mass concentration = molar concentration x molar mass

mass concentration=0.1 M,

molar mass= 204.233 g/mol

so to get 1L

mass conc = 204.233 x 0.1

= 20.4233g for 1L or 1000 ml

to get 6.00 ml

if 20.4233g is for 1000ml

then to 6.00 ml

= 20.4233 x 6 / 1000

= 0.123g for 6.00 ml

according to the equation below

NaOH(aq) + KHC8H4O4(aq) --> KNaC8H4O4(aq) + H2O(l)

number of moles of NaOH is equal to that of KHP

so the same amount will be needed too, which is

= 0.123g

6 0

2 years ago

State which statement is a physical change or a chemical change:

Oliga [24]

Answer:

Physical change: A,C ,D, F, H, I

Chemical Change: B, E, G, J, K

4 0

3 years ago

How to do dots and cross diagrams

Likurg_2 [28]

Answer:

Draw circles to represent the electron shell of each atom overlapping the circles where the atoms are bonded. Add dots to represent the outer electrons of one type of atom (H). Add crosses to represent the outer electrons of the other type of atom (Cl). Make sure the electrons are always in pairs.

6 0

2 years ago

The molar heat of fusion of gold is 12.550 kJ mol–1. At its melting point, how much mass of melted gold must solidify to release

KATRIN_1 [288]

The mass of melted gold to release the energy would be 3, 688. 8 Kg

<h3>How to determine the mass</h3>

The formula for quantity of energy is given thus;

Q = n × HF

Where n represents number of moles

HF represents heat of fusion

To find the number of moles, we have

235.0 = n × 12.550

number of moles = $\frac{235}{12. 550}$ = 18. 725 moles

Note that molar mass of Gold is 197g/ mol

Let's note that;

Number of moles = mass/ molar mass

Mass = number of moles × molar mass

Mass = 18. 725 × 197

Mass = 3, 688. 8 Kg

Thus, the mass of melted gold to release the energy would be 3, 688. 8 Kg

Learn more about molar heat of fusion here:

brainly.com/question/15634085

#SPJ1

8 0

1 year ago