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3 years ago

2 The substance has a mass of 0.50 kg.

Chemistry

1 answer:

katen-ka-za [31]3 years ago

5 0

Answer:

68000J/kg

Explanation:

Given parameters:

Mass of the substance = 0.5kg

Quantity of heat transferred to the body = 34000J

Unknown:

Specific latent heat of fusion = ?

Solution:

The specific latent heat is usually involve in phase changes;

H = mL

H is the quantity of heat supplied

m is the mass

L is the specific latent heat

Insert the parameters and solve;

34000 = 0.5 x L

L = $\frac{34000}{0.5}$ = 68000J/kg

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A glass was filled with 10 ounces of water, and 0.01 ounce of the water evaporated each day during a twenty-day period. What pe

liubo4ka [24]

Answer:

Explanation:

Original mass of water in glass = 10 ounces

amount that evaporates each day = 0.01 ounce

number of days = 20 days

Total amount that evaporated = 0.01 x 20 = 0.2 ounce

percentage of water that evaporated during this period = 0.2/10 x 100

= 2%

Hence, the percentage of the original amount of water evaporated during this period is 2%

7 0

3 years ago

The zero order reaction 2N2O→2N2+O2 has the reaction constant k is 6.28×10−3 molL s. If the initial concentration of N2O is 0.96

Talja [164]

Answer: The concentration of $N_2O$ in three significant figures will be 0.899 mol/L.

Explanation:

For the given reaction:

$2N_2O\rightarrow 2N_2+O_2$

The above reaction follows zero order kinetics. The rate law equation for zero order follows:

$k=\frac{1}{t}([A_o]-[A])$

where,

k = rate constant for the reaction = $6.28\times 10^{-3}\text{ mol }L^{-1}s^{-1}$

t = time taken = 10 sec

$[A_o]$ = initial concentration of the reactant = 0.962 mol/L

[A] = concentration of reactant after some time = ?

Putting values in above equation, we get:

$6.28\times 10^{-3}=\frac{1}{10}(0.962-[A])$

$[A]=0.899mol/L$

Hence, the concentration of $N_2O$ in three significant figures will be 0.899 mol/L.

5 0

3 years ago

What is the pH of a solution made by mixing 200 mL of 0.025M HCl and 150 mL of 0.050 M HCl?

seraphim [82]

Answer:

The answer to your question is pH = 1.45

Explanation:

Data

pH = ?

Volume 1 = 200 ml

[HCl] 1 = 0.025 M

Volume 2 = 150 ml

[HCl] 2 = 0.050 M

Process

1.- Calculate the number of moles of each solution

Solution 1

Molarity = moles / volume

-Solve for moles

moles = 0.025 x 0.2

result

moles = 0.005

Solution 2

moles = 0.050 x 0.15

-result

moles = 0.0075

2.- Sum up the number of moles

Total moles = 0.005 + 0.0075

= 0.0125

3.- Sum up the volume

total volume = 200 + 150

350 ml or 0.35 l

4.- Calculate the final concentration

Molarity = 0.0125 / 0.35

= 0.0357

5.- Calculate the pH

pH = -log [H⁺]

-Substitution

pH = -log[0.0357]

-Result

pH = 1.45

8 0

4 years ago

Which material has been recycled for over 3,000 years?

alexgriva [62]

Answer:

plastic

Explanation:

4 0

3 years ago

In a titration of 35.00 mL of 0.737 M H2SO4, __________ mL of a 0.827 M KOH solution is required for neutralization.

elena55 [62]

Answer:

In a titration of 35.00 mL of 0.737 M H₂SO₄, 62.4 mL of a 0.827 M KOH solution is required for neutralization.

Explanation:

The balanced reaction is

H₂SO₄ + 2 KOH ⇒ 2 H₂O + K₂SO₄

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) 1 mole of H₂SO₄ is neutralized with 2 moles of KOH.

The molarity M being the number of moles of solute that are dissolved in a given volume, expressed as:

$Molarity=\frac{number of moles}{volume}$

in units of $\frac{moles}{liter}$

then the number of moles can be calculated as:

number of moles= molarity* volume

You have acid H₂SO₄

35.00 mL= 0.035 L (being 1,000 mL= 1 L)
Molarity= 0.737 M

Then:

number of moles= 0.737 M* 0.035 L

number of moles= 0.0258

So you must neutralize 0.0258 moles of H₂SO₄. Now you can apply the following rule of three: if by stoichiometry 1 mole of H₂SO₄ are neutralized with 2 moles of KOH, 0.0258 moles of H₂SO₄ are neutralized with how many moles of KOH?

$moles of KOH=\frac{0.0258moles of H_{2} SO_{4}*2 moles of KOH }{1mole of H_{2} SO_{4}}$