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3 years ago

Please help me I'm so lost

Chemistry

2 answers:

andreev551 [17]3 years ago

6 0

The answer is "sound waves can spread out"

uranmaximum [27]3 years ago

4 0

I think the third one is your answer

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Potassium + Chlorine --> Potassium Chloride

ArbitrLikvidat [17]

Answer:

The balanced equation is 2K(s) + Cl2(g)→2KCl(s)

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3 years ago

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Which type of substance can be separated using a centrifuge?

Vaselesa [24]

C is the best answer

4 0

3 years ago

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The reaction of hydrogen(g) with fluorine(g) to form hydrogen fluoride(g) proceeds as follows: H2(g) + F2(g) 2 HF(g) When 0.647

Nata [24]

Answer: The value of $\Delta H$ for the reaction will be -537 kJ

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of hydrogen gas = 0.647 g

Molar mass of hydrogen gas = 2 g/mol

Putting values in above equation, we get:

$\text{Moles of hydrogen gas}=\frac{0.647g}{2g/mol}=0.324mol$

We are given:

Energy released for 0.324 moles of hydrogen reacted is 174 kJ

For the given chemical reaction:

$H_2(g)+F_2(g)\rightarrow 2HF(g)$

By Stoichiometry of the reaction:

When 0.324 moles of hydrogen gas is reacted, the energy evolved is 174 kJ

So, when 1 mole of hydrogen gas will react, the energy evolved will be = $\frac{174kJ}{0.324mol}\times 1mol=537kJ$

Sign convention of heat:

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

Hence, the value of $\Delta H$ for the reaction will be -537 kJ

6 0

3 years ago

What are the two variables that affect the electric force between two objects?

givi [52]

Explanation:

The electrical force between two objects is given by the formula as follows :

$F=\dfrac{kq_1q_2}{d^2}$

k is electrostatic constant

q₁ and q₂ are electric charges

d is distance between charges

So, the two force between two charged objects depends on the product of charges and distance between charges.

5 0

3 years ago

What did organizing information on the periodic table reveal?

Natalka [10]

Answer:

The groupings of elements in the periodic table reveal various trends, present in groups such as the alkali metals and noble gases, or the lanthanides and actinides. The periodic table can be used to find information on elements or predict the properties of as-of-yet undiscovered elements.

Explanation:

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3 years ago

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