PLEASE HELP!!!
a person measures the mass of a 10cm3 rock to be 15g. what is the density of the rock

Answer: You forgot to zero the balance

Explanation:

Answer:

case1.

The addition of acid and base leads to a change in pH of the water when adding to deionized water due to fact that acid and bases dissociated in dissolving in water. If the H+ ion increases in the water as acid addition hikes it, it will result in decreasing the pH value. The intensity of the acid also affects the dissociation of the ions.

case2

Buffers are normally formed by weak acid and its conjugate base, and adding acid to the buffer it absorbs the H+ ions so the pH will be lower and adding base or increase of OH- conjugate base resists the pH value to increase.

Answer:

[tex]V_1=0.0714L[/tex]

Explanation:

Hello there!

In this case, since we need to dilute the 1.75-M HCl, and the total number of moles remain unchanged, we can write:

[tex]n_1=n_2[/tex]

And in terms of volume and concentration:

[tex]C_1V_1=C_2V_2[/tex]

Thus, we can solve for the volume of the concentrated HCl as shown below:

[tex]V_1=\frac{C_2V_2}{C_1}[/tex]

Therefore, we plug in the data to get:

[tex]V_1=\frac{0.250M*0.500L}{1.75 M}\\\\V_1=0.0714L[/tex]

Best regards!

A severe storm would be most likely to damage a coastal area by causing pollution. Therefore, the correct option is option B.

The region where land joins the ocean, or even as a line defining the border between the land as well as the shoreline, is known as the coast, sometimes referred as the coastline and seashore. The terrain of the area's surroundings has an impact on shorelines, as do water-induced erosion processes like wave action.

The length of the shoreline on Earth is about 620,000 kilometers. Natural ecosystems' coasts are significant zones and frequently the site of a diverse range of biodiversity. They are home to significant ecosystems on land, such as freshwater and estuarine wetlands, that are crucial for the survival of bird populations or other land animals. A severe storm would be most likely to damage a coastal area by causing pollution.

Therefore, the correct option is option B.

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[tex]\displaystyle 1.67 \ mol \ KBr[/tex]

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[RxN - Balanced] 2K + Br₂ → 2KBr

[Given] 1.67 moles K

[Solve] moles KBr

Step 2: Identify Conversions

[RxN] 2 mol K → 2 mol KBr

Step 3: Stoichiometry

Answer:

True

Explanation:

yes magnetic feild lines is always combined

Answer:

m = 29.6 grams

Explanation:

Given that,

Number of moles = 0.540

The molar mass of manganese = 54.93 g/mol

We know that,

Number of moles = given mass/molar mass

[tex]m=n\times M\\\\m=0.540 \times 54.93\\\\m=29.6\ g[/tex]

So, the required mass of the Manganese is equal to 29.6 grams.

Answer:

Yes. At least some. There has been ups and downs in temperature ever since the Earth was created, and this is just another up in temperature. I do think that humans have made it worse though, with all of the greenhouse gases and things like that.

Answer:

Please see the attached picture.

Explanation:

1) Draw a benzene ring

2) On the first carbon, add a CH₂CH₃ (known as ethyl) since its location number is 1.

3) 'Dimethyl' refers to 2 methyl (CH₃) branches. The location numbers are 2 and 3, thus add a CH₃ on the 2nd and 3rd carbons.

Answer:

b. snake and earthworm

Explanation:

embryos are different from each other in early stages- all the others look similar

the answer is A I took the test

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

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Answer:

C I think

Explanation:

There will be no effect  if HI is removed from a reaction vessel containing this reaction at equilibrium. When HI remove, concentration of all three component is change and reach a new equilibrium stage.

H2 + I2 ⇄ 2HI

So, B is correct option.

The stage in reversible reaction at which rate of forward reaction is equal to rate of backward reaction is equal is called an equilibrium.

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Answer:

B: Barnacles ride on a gray whale's back to obtain food, and the hale is not harmed.

Explanation:

I got it right on Edge.

Answer:

Ca + 2 HCl -- CaCl2 + H2

Explanation:

There are two hydrogen on the right side, so we multiply the left side( HCl) by 2 to get 2 hydrogen on the left. This automatically gives you 2 Cl on left side and there are already 2 cl on the right side, so now this equation is balanced.

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.

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Answer:

From 00:11

Balance the Molecular Equation

From 01:35

Ions for the Complete Ionic Equation

From 03:04

Net Ionic EquationExplanation:

Answer:

5SiO2 + 2CaC2 → 5Si + 2CaO + 4CO2

Explanation:

When you are balancing an equation, you use coefficients to change the number of atoms of each type that are on each side of the equation.

You cannot change subscripts, the small numbers to the right of the substances. You can only add coefficients, the large numbers to the left of substances.

A balanced equation has the same number and type of atoms on both sides of the equation (the reactants on the left, the products on the right).

To begin, this equation has:

1 Si

2 O

1 Ca

2 C  

on the left and

1 Si

1 Ca

3 O

1 C

on the right. Those numbers don't match!

By adding coefficients we end up with 5 Si, 10 O, 2 Ca and 4 C on both sides.

Answer:

The correct answer is - 733.69 mg.

Explanation:

given:

The volume of ascorbic acid = 50 ml

The volume of NaOH = 20.74 ml

Molarity of NaOH = 0.201 M

formula = C6H8O6

Solution:

moles of NaOH for titration = molarity of NaOH × The volume of NaOH

= 0.201 × 20.74 × 10^-3

=4.16874 × 10^-3

then molecular weight of ascorbic acid

= 6 × 12+ 8×1+ 6× 16

=176g/mol

the molecular mass would be

= 4.16874 × 10^-3 × 176

= 733.69 × 10^-3 g

=733.69 mg

Answer:

2KCl+Fe---->FeCl2+2K

Explanation:

You can observe that the no.of atoms in reactant side is equal to that of products side of each element.

Answer:

0.64 L

Explanation:

Step 1: Given data

Step 2: Calculate the volume corresponding to 5.4 kg of oil

Density is an intrinsic property and it is equal to the quotient between the mass and the volume.

ρ = m/V

V = m/ρ

V = 5.4 kg/(8.5 kg/L) = 0.64 L

Answer:

c.

air molecules are close together and pressing on Earth’s surface.

Explanation:

i hope this helps!

Answer: There are 4.375 moles in 2.5 L of 1.75 M [tex]Na_2CO_3[/tex]

Explanation:

To calculate the number of moles for given molarity, we use the equation:

[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}[/tex]      

Molarity of solution = 1.75 M

Volume of solution = 2.5 L  

Putting values in equation , we get:

[tex]1.75M=\frac{\text{Moles of} Na_2CO_3}{2.5L}\\\\\text{Moles of }Na_2CO_3=1.75mol/L\times 2.5L=4.375mol[/tex]

Answer:

Option A. 9.4 L

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 8 L

Initial temperature (T₁) = 293 K

Final temperature (T₂) = 343 K

Final volume (V₂) =?

V₁ / T₁ = V₂ / T₂

8 / 293 = V₂ / 343

Cross multiply

293 × V₂ = 8 × 343

293 × V₂ = 2744

Divide both side by 293

V₂ = 2744 / 293

V₂ = 9.4 L

Therefore, the final volume of the gas is 9.4 L

Answer:

V₂ = 25.065 L

Explanation:

Given data:

Initial volume = 15L

Initial pressure = 1500 mmHg (1500/760 = 1.97 atm)

Initial temperature = 299 K

Final temperature = 350 K

Final volume = ?

Final pressure = 1050 mmHg (1050/760 = 1.38 atm)

Formula:

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

V₂ = P₁V₁ T₂/ T₁ P₂  

V₂ = 1.97 atm × 15 L × 350 K / 299 K × 1.38 atm

V₂ = 10342.5 atm .L. K / 412.62 K.atm

V₂ = 25.065 L