I need help with my chemistry but you can only choose one correct answer​

Answer:

melting

its true believe it you sheep

Answer:

1.8 × 10² J

Explanation:

Step 1: Given data

Step 2: Calculate the amount of heat absorbed (q)

We will use the following expression.

q = m × c × ΔT

q = 20 g × 0.48 J/g.°C × (29 °C - 10 °C) = 1.8 × 10² J

Answer:

Option A, The pH of the solution is 2.7 and the solution is acidic

Explanation:

As we know,

pH =  - log [H3O+]

Substituting the given values, we get

pH =  - log [2.1 x 10-3 M]

pH =  - (-2.678)

pH = 2.678 or 2.7

The solution is acidic as pH value is less than 7

Hence, option A is correct

Answer:

11.4

Explanation:

Density = Mass / Volume

Density = 35.4 / 3.11

Density = 11.38263666

As there are more number of digits after the decimal, you can round it to 3 significant figure.

Now, your value will be:

Density = 11.4

Answer:

option number 4. 'coral'

Explanation:

-

Answer: One with a pKa of 1.9

Hope this helps <3

P.S Fun Fact~~

There are only two words in the English language that have all five vowels in order: "abstemious" and "facetious."!

Answer:

Explanation:   Is there choises? H3PO4 / NaH2PO4 buffer with equal concentrations would form a buffer solution pH = 2.15

Answer:

molecules take up more space

Explanation:

that both the plastic & balloon have the same charge

Answer:

5.4 mL of acid need to be added to 14.6 mL of water.

Explanation:

We can calculate how many mL of acid are needed by using the C₁V₁=C₂V₂ formula:

Then we calculate how many mL of water have to be added in order to reach 20.0 mL:

Thus, 5.4 mL of acid need to be added to 14.6 mL of water.

Photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation.

mark me brainliestt :))

Answer:

Explanation:

How many mols do you have?

1 mol = 6.02 * 10^23 atoms

x mol = 6.25 * 10 ^32 atoms

1/x = 6.02*10^23 / 6.25 * 10^32        Cross multiply

6.02 * 10^23 * x = 1 * 6.25 * 10^32    Divide by 6.02 * 10^23

x = 6.25 * 10*32/ 6.02 ^10^23

x = 1.038 * 10^9 mols which is quite large.

Find the number of grams. (Use the value for copper on your periodic table. I will just use an approximate number.)\

1 mol of copper = 63 grams.

1.038 * 10^9 mols of copper = x

1/1.038 * 10^9 = 63/x         Cross multiply

x = 1.038 * 10^9 * 63

x = 6.54 * 10^10 grams of copper.

Answer:

C. Blood sugar increases b/c insulin lowers blood sugar when it rises too high

Explanation:

Insulin is highly needed by body to regular sugar levels (primarily to lower it when sugar levels rise up). I remember it like this "in" sulin means this hormones "pushes" the sugar inside the cells so that sugar level in the blood comes back to normal.

Therefore, if there is not enough insulin produced by pancreas, blood sugars will rise which can be fatal. That's why some diabetic patients take insulin shots to regulate their blood glucose levels.

Answer:

11,1

Explanation:

-log(1.3x10^-11)

The pH of a solution with a hydrogen ion concentration of 1.3X10^-11 is -11.1. Therefore, option A is correct.

The potential of hydrogen ion concentration is referred to as pH. a way to gauge how basic or acidic a material is. The pH scale represents from 0 to 14.

A pH value of 7 is considered neutral on this scale, which implies it is neither acidic nor basic. It is more than acidic if the pH value is below seven, and more basic if the pH value is above seven.

The pH can control the presence of nutrients, biological processes, microbial activity, and chemical behaviour.

Given:

Hydrogen ion concentration = 1.3X10^-11

pH = -log [H+]

pH = -log(1.3x10^-11)

pH = -11.1

Thus,-11.1 is the pH of a solution with a hydrogen ion concentration of 1.3X10^-11, option A is correct.

To learn more about the pH, follow the link;

https://brainly.com/question/15289741

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Answer:

dfdgfhgjghfdgsfdaafsgdhfjgkfjdgsasfdgfhghjgfdsafg

im 100% sure

Explanation:

Answer:

An increase in pressure would cause less volume and vice versa. They are inversely proportional.

Explanation:

This is due to Boyle's Law (and because an increase in pressure would increase the force on the container, however, if it's a closed container, it would burst)

Feel free to mark it as brainliest :D

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.

Answer:

1.22 J/g.°C

Explanation:

Step 1: Given data

Step 2: Calculate the specific heat of the metal (c)

A metal absorbs heat and, as a consequence, its temperature increases. We can calculate its specific heat using the following expression.

c = Q / m × ΔT

c = 570.4 J / 17.5 g × 26.8 °C = 1.22 J/g.°C

Answer:17.65 or 18 L

Explanation:

Answer:

0.616 moles of Fe₂(CO₃)₃ are produced when 200 g of FeCl₃ react

b. 1.

Explanation:

The balanced reaction is:

First we convert 200 grams of FeCl₃ into moles, using its molar mass:

Then we convert 1.23 moles of FeCl₃ into moles of Fe₂(CO₃)₃, using the stoichiometric coefficients of the balanced reaction:

The closest answer would be option b. 1.

Explanation:

[tex]FeCl₃ + (NH₄)₂CO₃ → NH₄Cl + Fe₂(CO₃)₃[/tex]

first balance the chemical equation

[tex]2FeCl₃ + 3(NH₄)₂CO₃ → 6NH₄Cl + Fe₂(CO₃)₃[/tex]

2 mole. 3 mole. 6mole. 1mole

2*162g of FeCl₃ produce 236 g of Fe₂(CO₃)₃

200g of of FeCl₃

produce 236/(2*162)*20=145.68 g of Fe₂(CO₃)₃

1 mole of Fe₂(CO₃)₃=236g

145.68g of Fe₂(CO₃)=1/236*145.68=}0.61mole

closest answer is b 1

b.1mole(s) of iron (III) carbonate [Fe2CO3)3] is/are produced in the balanced equation

Answer: Electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]

Explanation:

Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is also called the reaction where the exchange of electrons takes place.

An oxidation reaction is defined as the reaction in which a chemical species loses electrons takes place. In this reaction, the oxidation state of a substance gets increased.

A reduction reaction is defined as the reaction in which a chemical species gains electrons takes place. In this reaction, the oxidation state of a substance gets reduced.

For the given chemical reaction:

[tex]PbO_2+4HCl\rightarrow PbCl_2+Cl_2+2H_2O[/tex]

The half-reactions for this redox rection follows:

Oxidation half-reaction:  [tex]2HCl\rightarrow ClO_2 + 2e^-[/tex]

Reduction half-reaction:  [tex]PbO_2+2e^-\rightarrow PbCl_2[/tex]

Hence, electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]

Answer:

If you want to separate black grapes from the mixture of black and green grapes, then you will simply pick black grapes using your hands from the mixture. In this way you are actually using handpicking separation method.

Explanation:

Answer:

Here is your Answer.......

Explanation:

The Watson and Crick's ball-and-stick model of DNA best illustrates the role of creativity in scientific discovery

Answer:

Hydrocyanic acid, HCN.

Explanation:

A buffer is defined as the aqueous mixture of a weak acid and its conjugate base. Or a weak base and its conjugate acid. In the problem, we have a solution of potassium cyanide. The conjugate acid of potassium cyanide is hydrocyanic acid. A weak acid with pKa = 9.89.

That means, to convert the solution into a buffer we must add:

Answer:

83.3 L

Explanation:

Step 1: Given data

Capacity of the wine barrel (V): 22.0 gal

Step 2: Calculate how many liters of wine can be held in the barrel

To calculate the number of liters of wine that can be held in the barrel, we need to convert 22.0 gal to liters. We will use the conversion factor 1 gal = 3.79 L.

22.0 gal × 3.79 L/1 gal = 83.3 L