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3 years ago

Please help with 14-16 Thank you!

Chemistry

1 answer:

Natalka [10]3 years ago

4 0

I don't know about 14, but 15 is (4), because a liquid draws in heat to turn into a gas. 16 is (2), because to turn into a cold solid, something has to release heat.

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How do i find a ionic formula? for example Ca2+ & S2-

jeka94

Example #1 write the chemical formula for Calcium Oxide

Step 1

-Find the Atomic symbol of the metal and non-metal on the periodic table

CaO

Step 2

Find the charges for Calcium and Oxygen

which are Ca 2+ and O 2-

Step 3

Balance out the charges

They are already balanced out

Here´s the chemical formula for Calcium Oxide

CaO

Example 2 write the chemical formula for Aluminum Oxide

Step 1

-Find the Atomic symbol of the metal and non-metal on the periodic table

Step 2

Find the charges for Aluminum and Oxygen

Which are Al 3+ and O 2-

Step 3

Balance out the charges

You need 2 Aluminum and 3 Oxygen to balance the charges

Al 3+ O 2-

= 6 + O 2-

= 6-

Step 4

If you need more then one element to balance out the charges you identify that by using subscripts

Heres your chemical formula for Aluminum Oxide

$Al_{2} O_{3}$

8 0

3 years ago

_____ are factors that are not tested and remain constant. A. Dependent variables B. Controlled variables C. Independent variabl

stepan [7]

Answer:

B. Controlled variables

Explanation:

The Dependent sample t-test compares the mean score of measurements in one group to that of another other group. It mainly used when analyzing comparable sample units as it pairs repeatable observations within a time frame.

Controlled variables are factors that are not tested and remain constant. Some examples of controlled variables are temperature, pressure, volume etc

5 0

3 years ago

When of a certain molecular compound X are dissolved in of benzene , the freezing point of the solution is measured to be . Calc

puteri [66]

The question is incomplete. Here is the complete question.

When 2.10 g of a certain molecular compound X are dissolved in 65.0 g of benzene (C₆H₆), the freezing point of the solution is measured to be 3.5°C. Calculate the molar mass of X. If you need any additional information on benzene, use only what you find in the ALEKS Data resource. Also, be sure your answer has a unit symbol, and is rounded to 2 significant digits.

Answer: MM = 47.30 g/mol.

Explanation: There is a relationship between freezing point depression and molality. With this last one, is possible to calculate molar mass or molar weight of a compound.

Freezing Point Depression occurs when a solute is added to a solvent: the freezing point of the solvent decreases when a non-volatile solute is incremented.

Molality or molal concentration is a quantity of solute dissolved in a certain mass, in kg, of solvent. Its symbol is m and it's defined as

$m=\frac{moles(solute)}{kg(solvent)}$

Freezing point depression and molal are related as the following:

$\Delta T_{f}=K_{f}.m$

where

$\Delta T_{f}$ is freezing point depression of solution

$K_{f}$ is molal freezing point depression constant

m is molality

Now, to determine molar mass, first, find molality of the mixture:

$\Delta T_{f}=K_{f}.m$

$m=\frac{\Delta T_{f}}{K_{f}}$

For benzene, constant is 5.12°C/molal. Then

$m=\frac{3.5}{5.12}$

m = 0.683 molal

Second, knowing the relationship between molal and moles of solute, determine the last one:

$m=\frac{moles(solute)}{kg(solvent)}$

$mol(solute)=m.kg(solvent)$

mol(solute) = 0.683(0.065)

mol(solute) = 0.044 mol

The definition for Molar mass is the mass in grams of 1 mol of substance:

$n(moles)=\frac{m(g)}{MM(g/mol)}$

$MM=\frac{m}{n}$

In the mixture, there are 0.044 moles of X, so its molecular mass is

$MM=\frac{2.1}{0.044}$

MM = 47.30 g/mol

The molecular compound X has molecular mass of 47.30 g/mol.

7 0

3 years ago

This diagram illustrates the life cycle of a tomato plant. Which stage in this plant life cycle is the adult? Tomato Plant Life

GuDViN [60]

Answer:

the answer is A

Explanation:

hope it hlp

7 0

3 years ago

Which of the following claims may be made based on your observations? (You will recieve negative points for wrong answers.)

Ostrovityanka [42]

Answer:

D, E and F

Explanation:

About tetrachloro cobalt complexes, the following facts have been observed

Color of the tetrachloro cobalt complexes is blue.
They do not decompose on heating that means synthesis of tetra chloro is endothermic.

About hexa aqua cobalt complexes, the following facts have been observed

Color of the hexa aqua cobalt complexes is pink color.
They decompose on heating and remain stable on cooling that means process of synthesis of hexa aqua cobalt complexes is exothermic.

Based on above, the correct statements are:

The correct is chloro cobalt complex is blue and aqua cobalt

complex is pink.

The chloro complex is favored by heating.

If the chloro complex is a product, then the reaction must be endothermic.

The correct options are D, E and F.

8 0

3 years ago