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3 years ago

In the science lab, Sika combines two substances and determines that a chemical change has taken place. What

Chemistry

1 answer:

Lerok [7]3 years ago

4 0

Answer:

Evidence of chemical change is color change, smell,new matter created, gas created or heat or light being created.

Explanation:

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How many bananas are equal to 7.50 moles of bananas?

Veseljchak [2.6K]

Answer:

4.52×10^24

Explanation:

N = n × Na

where; N = no. of bananas

n = no. of moles

Na = Avogadro's constant

Which is 6.02×10^23

N = 7.5 × 6.02×10^23

N =4.515×10^24

7 0

2 years ago

Two unknown molecular compounds were being studied. A solution containing 5.00 g of compound A in 100. g of water froze at a low

LenaWriter [7]

Answer:

Compound B has greater molar mass.

Explanation:

The depression in freezing point is given by ;

$\Delta T_f=i\times k_f\times m$ ..[1]

$m=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Mass of solvent in kg}}$

Where:

i = van't Hoff factor

$k_f$ = Molal depression constant

m = molality of the solution

According to question , solution with 5.00 g of A in 100.0 grams of water froze at at lower temperature than solution with 5.00 g of B in 100.0 grams of water.

The depression in freezing point of solution with A solute: $\Delta T_{f,A}$

Molar mass of A = $M_A$

The depression in freezing point of solution with B solute: $\Delta T_{f,B}$

Molar mass of B = $M_B$

$\Delta T_{f,A}>\Delta T_{f,B}$

As we can see in [1] , that depression in freezing point is inversely related to molar mass of the solute.

$\Delta T_f\propto \frac{1}{\text{Molar mass of solute}}$

$M_A$

This means compound B has greater molar mass than compound A,

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3 years ago

Why do boys play with your emotions?

mamaluj [8]

I dont think always kow how to treat a woman right

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2 years ago

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Is it possible to transfer heat from a cold reservoir to a hot reservoir?

tankabanditka [31]

Answer is: B.) Yes, if work is done, this transfer process can take place.

For example, air conditioner involves a cyclic process that transfers heat from a cold reservoir to a hot reservoir, but with use of electricity.

Thermal conductuction is the transfer of heat through physical contact. Thermal conduction is the transfer of heat by microscopic collisions of particles. Heat spontaneously flows from a hotter to a colder body.

The process of heat conduction depends on four basic factors: the temperature gradient, the cross section of the materials involved, their path length and the properties of those materials.

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3 years ago

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Planetesimals are made from A. Rock B. Gas C. Stars D. Clouds

White raven [17]

A )rock is correct answer

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3 years ago

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