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3 years ago

Which of the following is true for compounds?

1 answer:

4 0

Compound are formed by two or more elements chemically combined. For example: H^2O is the water formula, this is a compound because you two elements which are Hydrogen and Oxygen and together they form a compound. The (^2) is the amount of atoms the formula has, in this case Hydrogen has two atoms and Oxygen is neutral.

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I need help with 1,2,3, and 4

Schach [20]

Answer:

Problem 1: 1.85atm

Problem 2: 110mL

Problem 3: 290 mL

Problem 4: 1.14 atm

Explanation:

Problem 1

1. Data

a) P₁ = 3.25atm

b) V₁ = 755mL

c) P₂ = ?

d) V₂ = 1325 mL

r) T = 65ºC

2. Formula

Since the temeperature is constant you can use Boyle's law for idial gases:

$PV=constant\\\\P_1V_1=P_2V_2$

3. Solution

Solve, substitute and compute:

$P_1V_1=P_2V_2\\\\P_2=P_1V_1/V_2$

$P_2=3.25atm\times755mL/1325mL=1.85atm$

Problem 2

1. Data

a) V₁ = 125 mL

b) P₁ = 548mmHg

c) P₁ = 625mmHg

d) V₂ = ?

2. Formula

You assume that the temperature does not change, and then can use Boyl'es law again.

$P_1V_1=P_2V_2$

3. Solution

This time, solve for V₂:

$P_1V_1=P_2V_2\\\\V_2=P_1V_1/P_2$

Substitute and compute:

$V_2=548mmHg\times 125mL/625mmHg=109.6mL$

You must round to 3 significant figures:

$V_2=110mL$

Problem 3

1. Data

a) V₁ = 285mL

b) T₁ = 25ºC

c) V₂ = ?

d) T₂ = 35ºC

2. Formula

At constant pressure, Charle's law states that volume and temperature are inversely related:

$V/T=constant\\\\\\\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}$

The temperatures must be in absolute scale.

3. Solution

a) Convert the temperatures to kelvins:

T₁ = 25 + 273.15K = 298.15K

T₂ = 35 + 273.15K = 308.15K

b) Substitute in the formula, solve for V₂, and compute:

$\dfrac{V_1}{T_1`}=\dfrac{V_2}{T_2}\\\\\\\\\dfrac{285mL}{298.15K}=\dfrac{V_2}{308.15K}\\\\\\V_2=308.15K\times285mL/298.15K=294.6ml$

You must round to two significant figures: 290 ml

Problem 4

1. Data

a) P = 865mmHg

b) Convert to atm

2. Formula

You must use a conversion factor.

1 atm = 760 mmHg

Divide both sides by 760 mmHg

$\dfrac{1atm}{760mmHg}=\dfrac{760mmHg}{760mmHg}\\\\\\1=\dfrac{1atm}{760mmHg}$

3. Solution

Multiply 865 mmHg by the conversion factor:

$865mmHg\times \dfrac{1atm}{760mmHg}=1.14atm\leftarrow answer$

3 0

3 years ago

Calculate the molarity of a solution prepared by dissolving 6.80 grams of AgNO3 in 2.50 liters of solution.

tester [92]

Answer:

0.016M

Explanation:

First we find the mole of AgNO3 by using the formula mass/molar mass..

Then we find molarity by the formula mole/volume...

I hope you get this..

7 0

3 years ago

All atoms of an element have the same number of ________. electrons neutrons protons protons plus neutrons

Cloud [144]

Answer:

protons

Explanation:

An element, by definition, always has the same number of protons. Sodium, element 11, has 11 protons. Anything with 11 protons is a sodium atom, regardless of the number of neutrons, electrons, or politicians.

6 0

2 years ago

NEED HELP ASAP LAST QUESTION CANT GET WRONG !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

yaroslaw [1]

A local community needs to provide more electricity for its growing population. Currently, the community's electricity needs are met by coal-burning power plants several kilometres away. Citizens are concerned that burning more coal will produce too much air pollution.

Which of the following could be used as an alternative energy resource to help minimise air pollution in this community?

A. hydroelectric energy

B. solar energy

C. wind energy

D. all of these 

8 0

2 years ago

Convert 0.00200 g into Mg and answer in scientific notation:

Masja [62]

Answer: $2.00x10^{2}$

Explanation: 1 gram is equal to 1000 Milligrams so

$0.00200g=\frac{1000mg}{1g}$

Since you go straight across its just multiplication so 0.00200x1000=200mg

To answer it in scientific notation it should just be $2.00x10^{2}$ mg

5 0

1 year ago