? I JUST DONT UNDERSTAND

Answer:

a. pH = 7.0

b. pH = 12.52

c. pH = 12.70

d. pH = 12.78

Explanation:

a. Deionized water has the [H⁺] of pure water = 1x10⁻⁷ (Kw = 1x10⁻¹⁴ = [H⁺][OH⁻] - [H⁺] = [OH⁻ -)

pH = -log[H⁺] = 7

b. Moles NaOH = 5x10⁻³L * (0.10mol / L) = 5x10⁻⁴moles OH⁻ / 0.015L = 0.0333M = [OH⁻]

-Total volume = 10mL+5mL = 15mL = 0.015L

pOH = -log[OH⁻] = 1.48

pH = 14-pOH

pH = 12.52

c. Moles NaOH = 0.010L * (0.10mol / L) = 1x10⁻³moles OH⁻ / 0.020L = 0.0500M = [OH⁻]

-Total volume = 10mL+10mL = 20mL = 0.020L

pOH = -log[OH⁻] = 1.30

pH = 14-pOH

pH = 12.70

d. Moles NaOH = 0.015L * (0.10mol / L) = 1.5x10⁻³moles OH⁻ / 0.025L = 0.060M = [OH⁻]

-Total volume = 10mL+15mL = 25mL = 0.025L

pOH = -log[OH⁻] = 1.22

pH = 14-pOH

pH = 12.78

296 g BaBr₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[Given] 8.56 × 10²³ formula units BaBr₂

[Solve] grams BaBr₂

Step 2: Identify Conversions

Avogadro's Number

[PT] Molar Mass of Ba - 137.33 g/mol

[PT] Molar Mass of Br - 35.45 g/mol

Molar Mass of BaBr₂ - 137.33 + 2(35.45) = 208.23 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

295.99 g BaBr₂ ≈ 296 g BaBr₂

Thank you agenthammerx for helping me with this question!

Answer:

296 g BaBr₂

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets

Parenthesis

Exponents

Multiplication

Division

Addition

Subtraction

Left to Right

Chemistry

Atomic Structure

Reading a Periodic Table

Moles

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

Using Dimensional Analysis

Explanation:

Step 1: Define

[Given] 8.56 × 10²³ formula units BaBr₂

[Solve] grams BaBr₂

Step 2: Identify Conversions

Avogadro's Number

[PT] Molar Mass of Ba - 137.33 g/mol

[PT] Molar Mass of Br - 35.45 g/mol

Molar Mass of BaBr₂ - 137.33 + 2(35.45) = 208.23 g/mol

Step 3: Convert

[DA} Set up:                                                                                                      

[DA] Multiply/Divide [Cancel out units]:                                                          

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

295.99 g BaBr₂ ≈ 296 g BaBr₂

Answer:

D. A pond freezing over is not a chemical reaction, it is a physical reaction.

Answer:

0.51 cal/g.°C

Explanation:

Step 1: Given data

Step 2: Calculate the temperature change

ΔT = 12.7 °C - 10.4 °C = 2.3 °C

Step 3: Calculate the specific heat of the liquid (c)

We will use the following expression.

c = Q / m × ΔT

c = 14 cal / 12 g × 2.3 °C = 0.51 cal/g.°C

Answer:

[tex]m_{Sn}=630.57gSn[/tex]

Explanation:

Hello!

In this case, according to the chemical reaction:

[tex]SnO_2+2H_2\rightarrow Sn+2H_2O[/tex]

We can evidence the 2:1 mole ratio between hydrogen and tin, thus, we perform the following stoichiometric setup to obtain the mass of produced tin:

[tex]m_{Sn}=21.46gH_2*\frac{1molH_2}{2.02gH_2}*\frac{1molSn}{2molH_2} *\frac{118.71gSn}{1molSn} \\\\m_{Sn}=630.57gSn[/tex]

Best regards!

Answer:

77.81 g of CuNO₃

Explanation:

6 CuNO₃  +  Al₂(SO₄)₃  ⇒  3 Cu₂SO₄  +  2 Al(NO₃)₃

This is your chemical equation.  We will need this information for converting from Al(NO₃)₃ to CuNO₃.

First, convert grams of Al(NO₃)₃ into moles using the molar mass.

[tex]44.0g*\frac{mol}{213.01g} = 0.2065mol[/tex]

Next, convert moles of Al(NO₃)₃ to moles of CuNO₃.  You can do this by using the stoichiometry (the numbers in front of the compounds).  For every 6 moles of CuNO₃, you will get 2 moles of Al(NO₃)₃, causing the ratio of CuNO₃ to Al(NO₃)₃ to be 6:2.

[tex]0.2065mol*\frac{6}{2} =0.6197mol[/tex]

Now that you moles of CuNO₃, convert this to grams using its molar mass.

[tex]0.6197 mol * \frac{125.56g}{mol} =77.81 g[/tex]

You will need 77.81 grams of CuNO₃ to produce 44.0 grams of Al(NO₃)₃.

Answer:

The amount of the first solution rick needs to mix together to create the love portion is 8.5 mL

Explanation:

So as to make the love potion, we have;

The percentage of carbonated water in the love portion = 40%

The percentage of green tea in the first solution = 65%

The percentage of carbonated water in the first solution = 15%

The percentage of whole milk in the first solution = 20%

The percentage of orange juice in the second solution = 17%

The percentage of lemonade in the second solution = 38%

The percentage of carbonated water in the second solution = 45%

Let 'x' represent the volume in mL of the first solution added to make the love portion, and let 'y' be the volume in mL of the second solution added to make the love portion, we have;

x + y = 51...(1)

0.15·x + 0.45·y = 0.40×51 = 20.4

0.15·x + 0.45·y = 20.4...(2)

Solving the system of simultaneous equation by making 'y' the subject of each of the equation gives;

For equation (1)

y = 51 - x

For equation (2)

y = 20.4/0.45 - (0.15/0.45)·x = 136 - 3·x

y = 136/3 - (1/3)·x

Equating the two equations of 'y', gives;

51 - x = 136/3 - (1/3)·x

51 - 136/3 = x - (1/3)·x

17/3 = (2/3)·x

(2/3)·x = 17/3

x = (3/2) × (17/3) = 17/2 = 8.5

x = 8.5

y = 51 - x = 42.5

y = 42.5

Therefore, the amount of the first solution rick needs to mix together to create the love portion, x = 8.5 mL

Answer:

Molecules : Mass

Explanation:

The first three answer choices correctly pair a unit with what it measures. Molecules are not used to measure mass; grams are.

Answer:

your finger becomes negatively charged

Explanation:

hope it helps. follow me

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 8.12×10²³ atoms are in  90.43 mole of copper.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

number of moles of copper=90.43 moles

Substituting all the given values in the above equation, we get

number of atoms/molecules= 90.43 × 6.022×10²³

number of atoms/molecules=8.12×10²³ molecules

Therefore, 8.12×10²³ atoms are in 90.43 mole of copper.

To know more about mole, here:

https://brainly.com/question/15209553

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Answer:

The deviation in the results will be too large when compared with the actual result

Explanation:

The effect this will have on the results of the samples run using this Calibration solution is that the deviation in the results will be too large when compared with the actual result that was supposed to be obtained. and this will also lead to wrong analysis by the technician .

This will cause a result that is very different from the actual result, which will lead to errors in the analysis.

We can arrive at this answer because:

As we can see from the question above, the lab technician used a much higher calibration than what was recommended in the lab. This will lead to inaccurate and incorrect results.

More information:

https://brainly.com/question/957129?referrer=searchResults

Answer:

I believe it is 5.00

Explanation:

Answer:

A zwitterion or a hybrid ion is an ion that has both a positive and negative charge and can act as either a base or an acid.

Explanation:

A zwitterion or a hybrid ion is an ion that has both a positive and negative charge and can act as either a base or an acid. The net charge on a zwitterion is zero since it has equal number of positive and negative charges.

Alanine, is a monoamino monocarboxylica acid that is diprotic when fully protonated. The carboxylic acid group, COOH and the amino group, NH₃⁺, are able to produce one proton each. At a pH equal to the isoelectric point of alanine, it exists mainly in the zwitterionic form with the α-amino group protonated as NH₃⁺ and the α-carboxyl group deprotonated as COO⁻ . This is because at the isoelectric point of alanine (6.0), pI is greater than the acid dissociation constant, pKa of the α-carboxyl group whereas, pI is less than the acid dissociation constant, pKa of the α-amino group, so the two groups are negatively and positively charged respectively.

Answer:

X axis shows the independent and Y axis shows the dependent.

Explanation:

Answer:

HPRT

Explanation:

HPRT catalyzes the salvage reactions of hypoxanthine and guanine with PRPP to form IMP and GMP

The formation of GMP from IMP requires oxidation at C-2 of the purine ring, followed by a glutamine-dependent amidotransferase reaction that replaces the oxygen on C-2 with an amino group to yield 2-amino,6-oxy purine nucleoside monophosphate, or as this compound is commonly known, guanosine monophosphate.

Answer:

Electrostatic

Explanation:

The forces that are overcome are the repulsive electrostatic forces between the protons (all charged positively).

Answer:

[tex]MM=150.71g/mol[/tex]

Explanation:

Hello there!

In this case, since the molar masses of chemical compounds allow us to understand the mass they have per mole of substance, for tin oxide, we can see it has one tin atom and two oxygen atoms; thus, for the calculation of this molar mass we multiply the atomic masses by the number of atoms and them add the results up:

[tex]MM=m_{Sn}+2m_O\\\\MM=118.71g/mol+2*16.00g/mol\\\\MM=150.71g/mol[/tex]

Best regards!

Answer:

d

Explanation:

Answer:

hopen it helps soo much thanks for the points

Answer:

12.76 g

Explanation:

Step 1: Write the balanced equation

4 Fes + 7 O₂ ⇒ 2 Fe₂O₃ + 4 SO₂

Step 2: Calculate the moles corresponding to 11.15 g of O₂

The molar mass of O₂ is 32.00 g/mol.

11.15 g × 1 mol/32.00 g = 0.3484 mol

Step 3: Calculate the moles of SO₂ produced from 0.3484 moles of O₂

The molar ratio of O₂ to SO₂ is 7:4.

0.3484 mol O₂ × 4 mol SO₂/7 mol O₂ = 0.1991 mol SO₂

Step 4: Calculate the mass corresponding to 0.1991 moles of SO₂

The molar mass of SO₂ is 64.07 g/mol.

0.1991 mol × 64.07 g/mol = 12.76 g

Answer:

the scientific name is Angiosperms

Explanation:

please mark brainliest

Answer:

The mass of 0.063*10⁻⁴ moles of aluminum sulphate  is 2.15*10⁻³ grams.

Explanation:

Aluminum sulfate Al₂(SO₄)₃ has a molar mass of 342.15 g/mol.

Molar mass is the amount of mass that a substance contains in one mole of a substance, which can be an element or a compound.

So in this case you can apply the following rule of three: if 342.15 grams are present in 1 mole of aluminum sulfate, how much mass is present in 0.063*10⁻⁴ moles of the compound?

[tex]mass of aluminum sulphate=\frac{0.063*10^{-4}moles*342.15 grams }{1 mole}[/tex]

mass of aluminum sulphate= 2.15*10⁻³ grams

The mass of 0.063*10⁻⁴ moles of aluminum sulphate  is 2.15*10⁻³ grams.

Answer:

A

I honestly think it's A, but I could be wrong. It might be B, but I don't think so.

Answer:

Longer bonds have lower attractive force

Answer:

B and D

Explanation:

Because its adaptions they need to survive in the cold.

Answer:

ch4+h2o----725°-->co+2h2

Answer:

[tex]n=0.00259 mol[/tex]

Explanation:

Hello there!

In this case, since the Faraday's constant is 96500 Coulombs per mole, we can set up the following process to obtain the moles in 250 Coulombs:

[tex]n=\frac{250C}{96500C/mol}\\\\n=0.00259 mol[/tex]

Best regards!