The overnight temperature in Polokwane drops from 11° C to -2° C. By how many degrees has the temperature dropped?​

Answers

Answer 1
11 - 13 = -2. The temperature has dropped by 13°C.

Related Questions

The orbits of the planets in our solar system are
not
a Elliptical, circular
b Circular, elliptical
C Circular, oval
d None of the above

Answers

Answer:

A

Explanation:

I don't know how to say how I got it.

Answer:

d

Explanation:

the orbits of the planets in our circular elliptical and circular

How many grams of KNO3 will dissolve in 100 g of water at 50° to make a saturated
solution

Answers

you would only need 110/2 = 55 grams of KNO3 to make a solution

The reproductive structure of a gymnosperm is the

Answers

Answer:

Angiosperms

Explanation

Angiosperms have male sex organs called stamens. On the end of the stamen is the anther. This is where pollen is made. The pollen has to be taken to the pistil or the female part of the flower.

Answer:

Cone

Explanation:

Your teacher takes a candle and cuts some wax from the bottom of it. She puts a bit of wax in a beaker and places it on a hot plate. Eventually, the wax melts and becomes a liquid. Do you think this a physical or a chemical change? Explain.

Answers

Answer:

It is a chemical change

Explanation:

Melting of wax is temporary and wax can settle again on cooling and turns into a solid. ... Hence it is a chemical change.

Answer:

physical

Explanation:

the wax is changing it's physical state by becoming a liquid, it isn't changing it's chemical makeup

Lemon juice is an example of
A. bound water
B. free water
C. hydrates
D. All of the above.

Answers

Answer:

B. Free water

b.....................

PLEASE HELP!! Answer whatever ones you can please and thank you!!!!

1. A gas with a volume of 4.0 L at a pressure of 2.03 atm is allowed to expand to a volume of 12.0 L. What is the pressure in atm in the container if the temperature remains constant. Please show work (including the equation you used).

2.The volume of a gas is 200 mL at 350.0 kPa pressure. What will the volume be when the pressure is reduced to 120.0 kPa, assuming the temperature remains constant. Please show all work for full credit. Please show work (including the equation you used).

3.What is the original pressure of a bike tire if the current pressure is 150 atm and the volume changed from 1000 mL to 700 mL. Please show work (including the equation you used).

Answers

These problems can be solved using the gas laws. The combined gas law states that PV/T = k, where P is the pressure, V is the volume, T is the temperature (in Kelvin), and k is a constant. From this relationship, you can figure out the change in pressure, volume, or temperature of a gas provided that one of those three parameters remains unchanged. This will be shown in the problems given.

1. Here, the pressure and volume of a gas change while the temperature remains constant. Since PV/T = k, if T is also constant, then the relationship becomes PV = k. In other words, the pressure and volume of a gas at a constant temperature are inversely proportional to each other. This can be expressed mathematically as [tex]P_1V_1=P_2V_2[/tex] (also called Boyle's Law), where P₁ and V₁ denote the initial pressure and volume, and P₂ and V₂ denote the final (or changed) pressure and volume, respectively.

We are given a gas with an initial pressure, P₁, of 2.03 atm and an initial volume, V₁, of 4.0 L. We are also told that the gas expands to a final volume, V₂, of 12.0 L. So, we are looking for P₂: The pressure of the gas when the volume has expanded from 4.0 to 12.0 L. From Boyle's Law,

[tex]P_2=\frac{P_1V_1}{V_2}[/tex].

Thus,

[tex]\[P_2=\frac{\left ( 2.03 \text{ atm} \right )\left ( 4.0 \text{ L} \right )}{\left ( 12.0 \text{ L} \right )}\] = 0.67 atm.[/tex]

Since the pressure and volume of a gas are inversely proportional, as one increases, the other decreases, and vice versa.

2. This is another Boyle's Law problem, but this time, we have to figure out what the final volume will be when the pressure of a gas is changed. Since the pressure is reduced, we can deduce that the volume must increase (notice the parallel with the previous question). We again turn to Boyle's Law, and this time we solve for V₂:

[tex]V_2=\frac{P_1V_1}{P_2}[/tex]

from which we obtain

[tex]\[V_2=\frac{\left ( 350.0 \text{ kPa} \right )\left ( 200 \text{ mL} \right )}{\left ( 120.0 \text{ kPa} \right )}\] = 583 mL.[/tex]

It's not clear whether 200 mL (V₁) should be assigned three significant figures or one. I gave the answer to three significant figures; the answer to one significant figure would be 600 mL.

3. We use Boyle's Law once more here, but our word problem has us working backwards (it's also not explicitly mentioned that temperature remains constant, but it should be reasonable to assume so). The current pressure of the gas inside the bike tire is 150 atm at a volume of 700 mL . But we want to know what the initial pressure of the gas was at a volume of 1000 mL. In other words, we want to solve for the P₁ in Boyle's Law:

[tex]P_1=\frac{P_2V_2}{V_1}.[/tex]

Since the volume of the gas had decreased from 1000 mL (V₁) to 700 mL (V₂), and the pressure and volume of a gas at a constant temperature are inversely proportional, we would expect the pressure of the gas to have increased; that is, our P₁ should be less than 150 atm.

[tex]\[P_1=\frac{\left ( 150 \text{ atm} \right )\left ( 700 \text{ mL} \right )}{\left ( 1000 \text{ mL} \right )}\] = 105 atm.[/tex]

What would be the volume, in liters, of 85.5 grams of carbon monoxide at STP?

Answers

the volume in liters of 85.5 grams of carbon monoxide at STP would be —— 68.4L

1. A green rat snake that lives in the grass and a brown rat snake that lives
in the desert is a form of
A. Human genetic modification
B. Selective breeding
C. Natural selection
D. Artificial breeding

Answers

Answer:

It is an example of natural selection (option c)

Natural selection is demonstrated by a green rat snake living within that grass as well as a brown rat snake living throughout the desert.

Natural selection:

The process throughout which communities of sentient creatures adapt but instead transform is known as natural selection. Persons within a demographic are inherently varied, which means they are all unique under certain manner.

This variance indicates that certain people have qualities that are more adapted to their surroundings over others.

Thus "Option C" is correct.

Find out more information about Natural selection here:

https://brainly.com/question/14485249

0.200 mol of nitric acid reacts with copper (II) oxide. A mass of 15.3g of copper (II) nitrate is produced.
Calculate the percentage yield of copper (II) nitrate.

Answers

Answer:

the percentage yield of Cu(NO3) 2 is 40%

will mark BRAINLYIST
please help

Answers

1.00mol is the correct answer

3.95 g of sugar (C6H12O6) is dissolved in water to make 158 mL of solution. Find the molarity.

Answers

Answer:

[C₆H₁₂O₆] = 0.139 M

Explanation:

Molarity si defined as a sort of concentration. It indicates the moles of solute that are contained in 1 L of solution.

We can also say, that molarity are the mmoles of solute contained in 1 mL of solution.

For this case, the solute is sugar (glucose). Let's determine M (mmol/mL)

(3.95 g . 1mol / 180g) . (1000 mmol / 1mol) / 158 mL

We determine moles, we convert them to mmoles, we divide by mL

M = 0.139 M

Moles = 3.95 g . 1mol / 180g → 0.0219 mol

We convert mL to L → 158 mL . 1L/1000mL = 0.158L

M = 0.0219 mol / 0.158L = 0.139 M

Sea water contains 2% salt (NaCl) by weight. Given that water has a

density of 1g/mL. Determine the concentration of salt in:


(a) mg/L , (b) ppm.

Answers

Answer:

a) Concentration of salt in mg/L = 2g/100mL

b) concentration in ppm = 20000 ppm

Explanation:

Percentage composition of salt by weight in water = 2%

Density of water = 1 g/mL

100 mL of water will has a mass of 100 g

Mass of salt in 100 g of water = 2% ×100 g = 2 g

Therefore, 2 g of salt is dissolved in 100 mL of solution

Concentration of salt in 100 mL of solution = 2g/100mL

a) Concentration in mg/L

Mass of salt = 2 g = 2000 mg

Volume of solution = 100 mL = 0.1 L

Concentration in mg/L = 2000 mg/0.1 L

Concentration in mg/L = 20000 mg/L

b) Concentration in ppm

1 ppm = 1mg/L

Therefore, concentration in ppm = 20000 ppm

Matching

Enter the letter of the box whose contents best match the description.

8

8

8

a

b

с

e

f

v a mixture of molecules

atoms of a pure elementa metal

molecules of an element

va solid compound

a mixture of elements

a. box a

b. box e

c. box b

d. box f

e. box d

f. box c

QUESTION 10

Answers

Answer:

a mixture of molecules - Box f

atoms of a pure elementa metal - Box D

a solid compound - Box C

a mixture of elements - Box A

Explanation:

Box a has mixture of elements which forms a solid like shape but there are different elements present in the box. The box f has mixture of molecules in which many atoms are combined together. Box c has solid compound with single element.

3NaHCO, +CHO - CH. Na 0, +300, +3H, 0.
Name one reactant and one product

Answers

Na AND 3 there one or C and 0

Sodium chloride is a ____ substance because the atoms within are arranged in repeating patterns.


work bank
- crystalline
- hydrogen bonds
- hydrophilic
- hydrophobic
- polar molecule
- solvent

Answers

An ionic solid is a crystalline solid composed of ions (even if the ions are polyatomic). NaCl is an example of an ionic solid

generators need sources of energy to produce electricity. which form of energy is a noble where source of energy

A. hydro (water) energy
B. geothermal energy
C. fossil fuel
D. wind energy ​

Answers

Answer:

B

Explanation:

Но Water Lewis steucture​

Answers

what are asking commet it and I might be able to help

draw a lewis structure for XZ2 (X has 6 valence electrons, F has 7 valence electrons)

Answers

Answer:

yhpcfjfkg original ogigoyy chandan

How would you prepare a 1 L solution of 3 M MgO?

Answers

Answer:  175.35g

Explanation:  A 3 M solution has 3 moles of solute per litre.

The mass of one mole of NaCl equals the MW of NaCl MW =  35.45 + 23 =58.45 g/mol

The mass of 3 moles is 58.45 g/mol ×3 mol=175.35 g NaCl  or  200 g rounded to one sigfig.

Acetic acid (ch3cooh) and trifluoroacetic acid (cf3cooh) are shown by these particulate models. the ka for trifluoroacetic acid is 104 times greater than acetic acid. use the models to account for the differences in magnitude for the ka constant. the green atoms are fluorine, the red atoms are oxygen, the black atoms are carbon, and the white atoms are hydrogen.

Answers

Answer:

See explanation

Explanation:

If we look at the models, we will see that the three fluorine atoms in CF3COOH are attached to the carbon that is next to the -COOH group.

As a result of the electron withdrawing effect of the three fluorine atoms, CF3COOH  is much more acidic (104 times more acidic) than CH3COOH. This is reflected in the value of the Ka for each acid.

This electron withdrawing effect of the three fluorine atoms also stabilizes CF3COO- much more than CH3COO-.

I visit the Grand Canyon __________I go to arizona.(once,whenever,wherever)​

Answers

the answer for your question is whenever

That's the answer. hope you have a great day

Can i get some help?

Answers

Answer:

Rabbit

Explanation:

I said rabbit because the snake feeds off the rabbit and that's where he gets his energy from. If the question asked you what is the primary source of energy in this food chain then the answer would be the sun. Since the question only asks you about the snake then the rabbit is the answer.

Hope this helps!

How many moles are there in 4.7 x 10^24 molecules of water?

Answers

Answer:

7.81 moles

Explanation:

(4.7×10^24 )×1 moles divided by 6.02×10^23 molecules

A 334 mL sample of hydrogen was collected over water at 23C on day when the atmospheric pressure was 756 mm Hg.The vapor pressure of water under these conditions is 17.54 mm Hg. What volume, in liters, will the dry hydrogen ( No water vapor) occupy at STP?

Answers

Answer:

0.299 L

Explanation:

We'll begin by calculating the pressure of dry gas. This can be obtained as follow:

Measured pressure = 756 mm Hg

Water vapor pressure = 17.54 mm Hg

Pressure of dry gas =?

Pressure of dry gas = (Measured pressure) – (Water vapor pressure)

Pressure of dry gas = 738.46 mmHg

Finally, we shall determine the volume occupied at STP. This can be obtained as follow:

Initial volume (V₁) = 334 mL = 334 / 1000 = 0.334 L

Initial pressure (P₁) = 738.46 mmHg

Initial temperature (T₁) = 23 °C = 23 °C + 273 = 296 K

Final pressure (P₂) = 760 mmHg

Final temperature (T₂) = 273 K

Final volume (V₂)

P₁V₁/T₁ = P₂V₂/T₂

738.46 × 0.334 / 296 = 760 × V₂/273

Cross multiply

296 × 760 × V₂ = 738.46 × 0.334 × 273

224960 × V₂ = 67334.2597

Divide both side by 224960

V₂ = 67334.2597 / 224960

V₂ = 0.299 L

Thus, the volume of the dry gas st STP is 0.299 L.

If 1.85 g of Mg(OH)2 reacts with 3.71 g of HCl,
how much MgCl2 is produced? What is the limiting
reactant?

If 5.26 L of nitrogen monoxide and 7.64 L of oxygen
are combined, what mass of nitrogen dioxide is
formed? Assume conditions are STP.

If 18.1 g of silicon tetrachloride reacts with 8.4 L of
hydrogen at STP, what mass of silicon is formed?

What mass of Cu(OH)2 is produced in the reaction of
7.6 g Cu(NO3)2 with 6.2 g of KOH?

What mass of carbon dioxide is formed when 64 kg
of ethylene is burned in 142 kg of oxygen?

please show work any answered question is helpful

Answers

Both of them are a hope this helps

Gases Test
Chemistry

Answers

Answer:

6.64 l is the answer.......

true or false. a short circuit cannot cause a fire​

Answers

Answer:

false

Explanation:

Answer:

False

Explanation:

A short circuit can cause a spark or fire.

Propane, C3H8, a fuel used in many outdoor grills, burns in oxygen to produce carbon dioxide gas, CO2, and water vapor, H2O, as shown in the reaction below. If 2.0 mol of propane are burned (reacted with oxygen), how many moles of carbon dioxide will be produced?

Answers

Answer:

6 moles of CO₂

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

C₃H₈ + 5O₂ —> 3CO₂ + 4H₂O

From the balanced equation above,

1 mole of C₃H₈ reacted to produce 3 moles CO₂.

Finally, we shall determine the number of mole of CO₂ produced by the reaction of 2 moles of C₃H₈. This can be obtained as follow:

From the balanced equation above,

1 mole of C₃H₈ reacted to produce 3 moles CO₂.

Therefore, 2 moles of C₃H₈ will react to produce = 2 × 3 = 6 moles of CO₂.

Thus, 6 moles of CO₂ were obtained from the reaction.

In an isolated system, mass can neither be
created or destroyed.
ube
FALSE
TRUE

Answers

Answer:

True

Explanation:

The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.

Hope it helps

Describe the effect of resonance on the amount of rotation that can occur in the main chain of your tripeptide (phenylalanine, alanine, and tyrosine), which affects protein folding.

Answers

Answer:

use research.

Explanation:

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