Help plz now !
Which statement explains why a chemical equation must be balanced?
A. It must show the reactants and products on the correct sides of
the reaction arrow.
B. It must show that the mass of each element involved is conserved
by a chemical reaction.
C. It must show how each chemical formula is written to accurately
represent each substance.
D. It must show that coefficients and subscripts can be used in
chemical formulas.

Answer:

pH= 1.17

Explanation:

The neutralization reaction between HBr (acid) and KOH (base) is given by the following equation:

HBr(aq) + KOH(aq) → KBr(aq) + H₂O(l)

According to this equation, 1 mol of HBr reacts with 1 mol of KOH. Then, the moles can be expressed as the product between the molarity of the acid/base solution (M) and the volume in liters (V). So, we calculate the moles of acid and base:

Acid:

M(HBr) = 0.15 M = 0.15 mol/L

V(HBr) = 50.0 mL x 1 L/1000 mL = 0.05 L

moles of HBr = M(HBr) x V(HBr) = 0.15 mol/L x 0.05 L = 7.5 x 10⁻³ moles HBr

Base:

M(KOH) = 0.25 M = 0.25 mol/L

V(HBr) = 13.0 mL x 1 L/1000 mL = 0.013 L

moles of HBr = M(HBr) x V(HBr) = 0.25 mol/L x 0.013 L = 3.25 x 10⁻³ moles KOH

Now, we have: 7.5 x 10⁻³ moles HBr > 3.25 x 10⁻³ moles KOH

HBr is a strong acid and KOH is a strong base, so they are completely dissociated in water: the acid produces H⁺ ions and the base produces OH⁻ ions. So, the difference between the moles of HBr and the moles of KOH is equal to the moles of remaining H⁺ ions after neutralization:

moles of H⁺ = 7.5 x 10⁻³ moles HBr - 3.25 x 10⁻³ moles KOH = 4.25 x 10⁻³ moles H⁺

From the definition of pH:

pH = -log [H⁺]

The concentration of H⁺ ions is calculated from the moles of H⁺ divided into the total volume:

total volume = V(HBr) + V(KOH) = 0.05 L + 0.013 L = 0.063 L

[H⁺] = (moles of H⁺)/(total volume) = 4.25 x 10⁻³ moles/0.063 L = 0.067 M

Finally, we calculate the pH after neutralization:

pH = -log [H⁺] = -log (0.067) = 1.17

Answer:

CH4

Explanation:

if it is wrong, i blame my brain

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 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:

Longer bonds have lower attractive force

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:

B and D

Explanation:

Because its adaptions they need to survive in the cold.

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:

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

The equilibrium partial pressure of HF is 0.55 atm.

The equation of the reaction is;

        H2(g) + F2(g) ⇄ 2HF

I         2           1             0

C       -x           -x            +x

E     2 - x        1 - x           x

We know that;

pH2 = 2.0 atm

PF2 =  1.0 atm

pHF = ??

Kp = 0.45

So;

Kp = (pHF)^2/pH2. pF2

0.45 = x^2/(2 - x) (1 - x)

0.45 =  x^2/x^2 - 3x + 2

0.45(x^2 - 3x + 2) = x^2

0.45x^2 - 1.35x + 0.9 =  x^2

0.55 x^2 + 1.35x - 0.9 = 0

x = 0.55 atm

Learn more about equilibrium: https://brainly.com/question/3980297

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:

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:

A

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

Answer:

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

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

Answer:

Explanation:

metamorphic

Answer:

[tex]Cs^+[/tex]

Explanation:

Cesium Lewis dot structure would look like this:

·Cs,  because it only has one valence electron. But, since it has a plus, that means we lost an electron. So, we have to get rid of the dot and you have:

[tex]Cs^+[/tex]

Answer:

Freezing

Explanation:

When a liquid goes to a solid, this process is called freezing.

Answer:

The water molecules get condensed and form a solid matter called ice. This process is called Condensation.

Answer:

ch4+h2o----725°-->co+2h2

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:

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

Explanation:

Answer:

the scientific name is Angiosperms

Explanation:

please mark brainliest

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

#SPJ2

Answer:

your finger becomes negatively charged

Explanation:

hope it helps. follow me

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