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4 years ago

What can a drop of liquid mercury be described as?

2 answers:

8 0

A drop of iquid mercury is D. a pure substance and an element. This is because mercury is an element which exists as liquid in the normal or standard conditions. It is a metal that is toxic to all environments. It is pure because it is composed only of one kind of substance.

mezya [45]4 years ago

6 0

Answer: D) a pure substance and an element

Explanation:

Mercury is an element which is composed of similar atoms and is a pure substance.

Element is a pure substance which is composed of atoms of similar elements.

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.

Mixtures are impure substances and are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.

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Gases with high molecular weights diffuse more slowly than gases with lower molecular weights.

Rom4ik [11]

The answer to this item is TRUE. This can be explained through the Graham's law. This law states that the rate at which gases diffuse is inversely proportional to the square root of their densities which is also related to their molecular masses.

7 0

3 years ago

Read 2 more answers

Based on the information above, which statement provides evidence that a chemical reaction has occurred?

Vesna [10]

Answer: Atoms that make up reactants rearrange into new products

Explanation:

A chemical reaction is the process of breaking down the chemical bonds of the reacting substances which are commonly called as reactants and making new bonds to form new substances commonly called as products.

The products will contain the same atoms as there are in the reactants but the bonds will rearrange to form different substances.

Every chemical reaction is accompanied with absorption or release of energy.

3 0

3 years ago

How many grams of aluminum chloride are needed to react completely with 1.084g lithium sulfide?

Oksi-84 [34.3K]

Molar mass :

Li₂S = 45.947 g/mol

AlCl₃ = 133.34 g/mol

3 Li₂S + 2 AlCl₃ = 6 LiCl + Al₂S₃

3 * 45.947 g Li₂S ----------> 2 * 133.34 g AlCl₃
1.084 g Li₂S ----------------> ?

Mass Li₂S = 1.084 * 2 * 133.34 / 3 * 45.947

Mass Li₂S = 289.08112 / 137.841

Mass Li₂S = 2.0972 g

hope this helps!

5 0

3 years ago

By titration, it is found that 31.7 mL of 0.145 M NaOH(aq) is needed to neutralize 25.0 mL of HCl(aq). Calculate the concentrati

arlik [135]

Answer:

0.184 M

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

HCl + NaOH —> NaCl + H2O

From the balanced equation above, the following data were obtained:

Mole ratio of the acid, HCl (nA) = 1

Mole ratio of the base, NaOH (nB) = 1

Next, the data obtained from the question. This includes:

Volume of the base, NaOH (Vb) = 31.7 mL Molarity of the base, NaOH (Mb) = 0.145 M

Volume of the acid, HCl (Va) = 25.0 mL

Molarity of the acid, HCl (Ma) =?

Finally, we shall determine the molarity of the acid (HCl) as shown below:

MaVa /MbVb = nA/nB

Ma × 25 / 0.145 × 31.7 = 1

Cross multiply

Ma × 25 = 0.145 × 31.7

Ma × 25 = 4.5965

Divide both side by 25

Ma = 4.5965 / 25

Ma = 0.184 M

Therefore, the molarity of the acid (HCl) is 0.184 M

6 0

3 years ago

What is the percent yield of LiCl if I produced 30.85g LiCl and my theoretical yield was calculated to be 35.40g LiCl?

marissa [1.9K]

Answer:

87.15%

Explanation:

To find percent yield, we can use this simple equation

$\frac{Actual}{Theoretical} *100$

Where "Actual" is the amount in grams actually collected from the reaction, and "Theoretical" is, well, the theoretical amount that should have been produced.

They give us these values, so to find the percent yield, just plug the numbers in.

$\frac{30.85}{35.40} *100\\\\ =87.15$

So, the percent yield is 87.15%

An easy trick to remember how to do this is just to divide the smaller number by the bigger number and move the decimal back two places. If you have a percent yield greater than 100%, something is wrong in the reaction.

7 0

3 years ago