Congratulations you have worked hard and now you are done with the year! I am so proud of you!

Answers

Answer 1

Answer:

lololol

Explanation:


Related Questions

ok so i need a reasoning on What evidence have you discovered to explain how the curve of Earth’s surface affects temperatures on Earth?

Answers

The equator gets the most sun and has the warmest climate. This has to do with the tilt of the Earth on it’s axis. As you go north or south from the equator toward the poles the Earth’s temperature gets colder. It is harder for the sun’s direct rays & the curvature of the Earth to reach these points This has to do with the direct sunlight that reaches the equator. Think of a ball, or take a flashlight & shine it on a ball to see this yourself from different angles. The angle of the sun on the the Earth also causes different seasons.

Describe how to test your unknown salt mixture for the presence of
Na3PO4.12H2O.​

Answers

Na3PO4*12H2O + BaCl2*2H2O = Ba3(PO4)2 + NaCl + H2O

add barium chloride to your Na3PO4.12H2O a white precipitate of Ba3(PO4)2 will be formed wrt salt(NaCl) and water(H20) if Na3PO4.12H2O. will be there.

How many grams of ammonium fluoride, , must be dissolved to prepare 300. mL of a 0.234 M aqueous solution of the salt

Answers

Answer:

24.24 g

Explanation:

First we calculate how many moles are there in 300 mL of a 0.234 M solution, using the definition of molarity:

Molarity = moles / liters

Converting 300 mL to L ⇒ 300 mL / 1000 = 0.300 L

0.234 M = moles / 0.300 Lmoles = 0.78 moles

Then we convert 0.78 moles of NH₄F into grams, using its molar mass:

0.78 mol * 31.073 g/mol = 24.24 g

define perodic table what are period and groups​

Answers

Answer:

period is a horizontal row of the periodic table. There are seven periods in the periodic table, with each one beginning at the far left.

Explanation:

maaf kalo salah

In model periodic table the atoms are arranged wrt atomic number, there chemical behaviour, and properties.

The horizontal rows of periodic table are known as periods.

The vertical line of periodic table are knows as groups.

How many dots are drawn in a Lewis dot structure for elements in group 2 of the periodic table?

Answers

1 becasuevof one vvalence shell

what is the atomic mass of an element with 40 protons 40 electrons and 46 neutrons

Answers

Answer:

The 40 represents the atomic number and the number of proton in Zirconium. The "Zr" on the tile is the symbol of the elementp

A 15.67 g sample of a hydrate of magnesium carbonate was heated, without decomposing the carbonate, to drive off the water. The mass was reduced to 7.58 g. What is the name of the hydrate

Answers

Answer:

The correct answer is MgCO₃.5H₂O.

Explanation:

Based on the given information,

The mass of hydrate of magnesium carbonate given is 15.67 grams, and the mass of anhydrous magnesium carbonate given is 7.58 grams.

Now the mass of water will be,

= 15.67 grams – 7.58 grams

= 8.09 grams

The molecular mass of magnesium carbonate is 84.32 grams, the moles of MgCO₃ can be determined by using the formula,

Number of moles = Mass/Molecular mass

Moles of MgCO₃ = 7.58/84.32

= 0.0898 moles

Similarly, the number of moles of water will be,

Moles of H₂O = 8.099/18.02

= 0.4489 moles

After getting the values, there is a need to choose the smaller value and use it to divide both the values to get the ratio,

MgCO₃ = 0.0898/0.0898 = 1

H₂O = 0.4489/0.0898 = 4.9 or 5

Thus, the molecular formula for the hydrate will be MgCO₃.5H₂O.

How many moles of solute are in a 1.50 M solution of HCl with a volume of 7.98 liters?

Answers

Answer:

[tex]\boxed {\boxed {\sf x\approx 12.0 \ moles \ HCl}}[/tex]

Explanation:

Molarity is a measure of concentration in moles per liter.

[tex]molarity= \frac{moles \ of \ solute}{liters \ of solution}[/tex]

We know the solution has a volume of 7.98 liters and it has a molarity of 1.50 M HCl.

1 molar (M) is 1 mole per liter, so the molarity is also 1.50 moles of HCl per liter.

We know 2 values for the variables, but the value for moles of solute is unknown, so we use x.

molarity= 1.50 mol HCl/L moles of solute=xliters of solution = 7.98 L

Substitute the values into the formula.

[tex]1.50 \ mol \ HCl/L=\frac{x}{7.98 \ L}[/tex]

We are trying to solve for x, the moles of solute, so we must isolate the variable. It is being divided by 7.98 liters and the inverse of division is multiplication. Multiply both sides of the equation by 7.98 liters.

[tex]7.98 \ L *1.50 \ mol \ HCl/L=\frac{x}{7.98 \ L} * 7.98 \ L[/tex]

[tex]7.98 \ L *1.50 \ mol \ HCl/L=x[/tex]

The units of liters (L) cancel each other out.

[tex]7.98 *1.50 \ mol \ HCl=x[/tex]

[tex]11.97 \ mol \ HCl=x[/tex]

The original measurements of molarity and volume both have 3 significant figures, so our answer must have the same. For the number we found, that is the tenths place.

The 9 in the hundredth place tells us to round the 1 to a 2. We leave a 0 in the tenths place to ensure there are 3 significant figures.

[tex]12.0 \ mol \ HCl \approx x[/tex]

There are approximately 12.0 moles of solute in the solution.

help me pls i really need help

Answers

Answer:

Veins

Explanation:

Veins carry blood to the heart while arteries carry away from the heart

I dont understand this

Answers

Answer:

me too

Explanation:

The last one Metallic bonding

How many moles of SO2 will be produced from 11.5 moles of O2?

Answers

Explanation:

Respuesta: La masa atómica del carbono (C) es 12 g/mol; para el oxígeno (O) es de 16 g/mol. Esto significa que 6.022 x 1023 átomos de carbono pesan 12 gramos. Según esto, el peso molecular del CO2 es: 12 g/mol [C] + 2 x 16 g/mol [O2] = 44 g/mol

does anyone know this??

Answers

Answer: C2H6O

Explanation: It is C2H6O with a molar mass of 46.07 g/mol.

What does the reproductive system control?

Answers

Sperm and also sex what type of question is that lol

please answer all three of these questions ​

Answers

1 is chemical energy cause thats what gas and electric stoves are

2 is convection

3 is c

Answer:

I think it's 1.D

2.C

3.C

my apologies if it's incorrect

When you test starch with Barfoed’s reagent, what would be the answer, positive or negative?

Answers

Answer:

It would test positive.

NO LINKS PLEASE
1. What are the reactants at the start of this chemical reaction? What do you start with?
2. What are the products at the end of this chemical reaction? What do you end with?
3. If the total mass of the reactants equals 150 grams, what would the total mass of the
products be?

Answers

Answer:

1.The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products

2.The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products

3.The law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. For example, the mass of sodium plus the mass of chlorine that reacts with the sodium equals the mass of the product sodium chloride.

8. What was the original concentration in the BHL sample, if the dilution is 1:500 and the concentration 0.07 mg/ml

Answers

Answer:

The original concentration is "35 mg/ml".

Explanation:

According to the question,

The solution is diluted,

= 1:50

The initial volume,

V1 = 1 ml

Final concentration,

= 0.07 mg

then,

The final volume,

V2 = 500 ml

As we know,

⇒ [tex]V_1N_1=V_2N_2[/tex]

or,

⇒ [tex]N_1=\frac{V_2N_2}{V_1}[/tex]

On substituting the values, we get

⇒       [tex]=\frac{500\times 0.07}{1}[/tex]

⇒       [tex]=\frac{35}{1}[/tex]

⇒       [tex]=35 \ mg/ml[/tex]

A 0.07 mg/mL BHL solution was prepared by performing a 1:500 dilution on a 35 mg/mL solution.

A 1:500 dilution was carried out to prepare a 0.07 mg/mL BHL solution. We can find the concentration of the initial solution using the dilution rule.

What is the dilution rule?

It is an equation that relates the concentration and volume of a concentrated and a dilute solution. The mathematical expression is:

C₁ × V₁ = C₂ × V₂

where,

C₁ is the concentration of the concentrated solution.V₁ is the volume of the concentrated solution.C₂ is the concentration of the dilute solution.V₂ is the volume of the dilute solution.

C₁ = C₂ × (V₂/V₁)

C₁ = 0.07 mg/mL × (500/1) = 35 mg/mL

A 0.07 mg/mL BHL solution was prepared by performing a 1:500 dilution on a 35 mg/mL solution.

Learn more about dilution here: https://brainly.com/question/1615979

BRAINISEST & 10 POINTS

Answers

Answer:

In order from left to right, 7 (gamma), 5 (ultraviolet, now continue pattern), 4, 6, 2, 3, 1.

When water and alcohol are mixed, the final volume is less than the total of volume of alcohol plus water added due to .......​

Answers

Answer:

molecules take up more space

13. Which of the following correctly provides the names and formulas of polyatomic ions?
chromate: Cro42 -; dichromate: Cr2O7 2 -
O nitrite: NO -; nitrate: NO2
sulfite: S 2-; sulfate: SO3
O carbonate: HCO3 -; bicarbonate: C03

Answers

Mirror no :HCO3
Answer HCO3

What volume of chlorine gas at 27 °C, 812 mmHg, is required to react with an excess of carbon disulfide so that 5.00kJ of heat is evolved?

Answers

Answer:

The correct answer is 1.21 L.

Explanation:

Based on the given information, the reaction will be,

CS2 (l) + 3Cl2 (g) ⇒ CCl4 (l) + S2Cl2 (l)

By using the standard values of the substances, the standard enthalpy of the reaction is,

ΔH° = [(-139.5) + (-58.5) – 0 – (87.3)] kJ/mol

= -285.3 kJ/mol

The amount of heat evolved for 3 moles of chlorine reacted us 285.3 kJ.

Now the number of moles of chlorine needed to react to produce 5.00 kJ is,

= 5.00 kJ × 3 mol Cl2/285.3 kJ

= 0.0526 mol Cl2

Now the volume of chlorine gas at 27degree C and 812 mmHg will be,

Volume = 0.0526 mol Cl2 × 0.0821 Latm/mol K × 300 K/ 1.07 atm

= 1.21 L

What is predicted to happen if the permafrost in the Arctic melts?

Answers

Answer: It is causing erosion, landslides, and craters. If this keeps up the ice in the artic will eventually be gone

Explanation:

Pick the correct statement about the pure water. Group of answer choices Pure water contains no ions. Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O ] ions. Pure water contains larger amounts of hydroxide [OH-] than hydronium [H3O ] ions. Pure water is an electrolyte. Pure water contains smaller amounts of hydroxide [OH-] than hydronium [H3O ] ions.

Answers

Answer:

Pure water contains no ions.  TRUE

Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions.  TRUE

Explanation:

This is the equilibrium for pure water:

2H₂O  ⇄  H₃O⁺  +  OH⁻          Kw

We see that pure water has no Ions. Pure water can not conduct electricity.

Generally ionized water comes from the water tap.

Another feature of pure water is pH.

Definetely pH of pure water is : 7

As pH = 7, [H₃O⁺] = 1×10⁻⁷

Then, [OH⁻] = 1×10⁻⁷

This is reazonable because Kw is 1×10⁻¹⁴ and Kw = [H₃O⁺] . [OH⁻]

In conclussion:

Pure water contains no ions.  TRUE

Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions.  TRUE

Pure water contains larger amounts of hydroxide [OH-] than hydronium [H3O+] ions.  FALSE

Pure water is an electrolyte. FALSE

Pure water contains smaller amounts of hydroxide [OH-] than hydronium [H3O ] ions. FALSE

Hdhduhdhdudbbdhhdhdhdhdjjdhdhduuxhxuxuxuxuux

Answers

Answer:

dfdgfhgjghfdgsfdaafsgdhfjgkfjdgsasfdgfhghjgfdsafg

im 100% sure

Explanation:

Given the reaction: N2 + O2 = 2NO for which the Keq at 2273 K is 1.2 x 10-4
a. Write the equilibrium constant expression for the reaction.
b. Write the equation that would allow you solve for the concentration of NO.
c. What is the concentration of NO if [NZ] = 0.166M and [02] = 0.145M?

Answers

Answer:

(a): The expression of equilibrium constant is [tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]

(b): The equation to solve the concentration of NO is [tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex]

(c): The concentration of NO is 0.0017 M.

Explanation:

The equilibrium constant is defined as the ratio of the concentration of products to the concentration of reactants raised to the power of the stoichiometric coefficient of each. It is represented by the term [tex]K_{eq}[/tex]

(a):

The given chemical equation follows:

[tex]N_2+O_2\rightarrow 2NO[/tex]

The expression for equilbrium constant will be:

[tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]

(b):

The equation to solve the concentration of NO follows:

[tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex]            ......(1)

(c):

Given values:

[tex]K_{eq}=1.2\times 10^{-4}[/tex]

[tex][N_2]_{eq}=0.166M[/tex]

[tex][O_2]_{eq}=0.145M[/tex]

Plugging values in equation 1, we get:

[tex][NO]=\sqrt{(1.2\times 10^{-4})\times 0.166\times 0.145}[/tex]

[tex][NO]=\sqrt{2.88\times 10^{-6}}[/tex]

[tex][NO]=0.0017 M[/tex]

Hence, the concentration of NO is 0.0017 M.

Explain why this combination of compounds can or cannot make a buffer solution. Hint: apply definition of a buffer, mechanism of its action and consider whether the compound is acid (weak/strong) or base (weak/strong). HF (0.2 mol) and NaOH (0.1 mol)

Answers

Answer:

This combination can make a buffer

Explanation:

A buffer is defined as an aqueous mixture of a weak acid and its conjugate base, or vice versa.

In the problem, HF is a weak acid, and its conjugate base is F⁻.

When NaOH reacts with HF, F⁻, Na⁺ and H₂O are produced as follows:

NaOH + HF → F⁻ + Na⁺ + H₂O

As there are initially 0.2mol of HF and 0.1mol NaOH, after the reaction you will have:

0.1mol HF and 0.1mol F⁻. As both, the weak acic and the conjugate base are present:

This combination can make a buffer

he correct statements about thermal conductivity are: A. The thermal conductivity of metals is generally higher than that of liquids. B. The thermal conductivity of solids is generally higher than that of liquids. C. The thermal conductivity of gases is generally higher than that of liquids.

Answers

Answer: The correct statements about thermal conductivity are:

The thermal conductivity of metals is generally higher than that of liquids.The thermal conductivity of solids is generally higher than that of liquids.

Explanation:

The rate at which transfer of heat takes place from one object to another by conduction over a unit cross section area of a material is called thermal conductivity.

Hence, more is the distance between atoms of a substance less will be its thermal conductivity. This is because more is the space between molecules of a substance more will be their random motion due to which there will be less effective energy transport.

The thermal conductivity of metals is very high than liquids.

Also, the thermal conductivity of solids is generally higher than that of liquids.

As gases have more space between its molecules so they have less thermal conductivity.

Thus, we can conclude that the correct statements about thermal conductivity are:

The thermal conductivity of metals is generally higher than that of liquids.The thermal conductivity of solids is generally higher than that of liquids.

Examples of a chemical reaction?

Answers

Answer:

Decomposition of normal salt ( sodium chloride )

Formation of water from hydrogen peroxide.

Combustion of propane

e.t.c

A chemist adds 255 .0 mL of a M copper(II) sulfate solution to a reaction flask. Calculate the mass in grams of copper(II) sulfate the chemist has added to the flask. Round your answer to significant digits.

Answers

Answer:

The correct answer is 40.7 grams.

Explanation:

Based on the given information, the volume of copper sulfate added to the solution is 255 ml or 0.255 L. The molarity of copper sulfate is not given, so let us consider it to be 1 M, which can also be written as 1 moles per liter.

The moles of copper sulfate can be determined by using the formula,

Moles = Molarity * Volume in Liters

Moles of CuSO4 = 1 moles/Liter * 0.255 L

Moles of CuSO4 = 0.255 moles

The mass of CuSO4 added in the solution will be,

Mass of CuSO4 = Moles * Molecular mass

= 0.255 moles * 159.609 grams per mole

= 40.7 grams.

From the following data ,determine of formation for diborane(B2H2(g), at 25
B2H2(g) 3O2(g)(B2O3(S)3H2O(g) ,=-1941kJ
2B(s) O2(g) (B2O3(s) ,=-2368 kJ
H2(g) O2(g) (H2O(g) , =-241.8 kJ​

Answers

2Bs believe is the answer I’m not sure tho
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