does anyone have the 2020 paper for chemistry

Answers

Answer 1

Answer:

Erm.......... can you clarify what "paper", you just said "paper" there's a lot.

Explanation:


Related Questions

What temperature is absolute zero in Fahrenheit?

Answers

Answer:

-460 Im pretty sure

Explanation:

all organisms of the same species have the same traits true or false? explain

Answers

Answer:   It would be true

Explanation:        Individuals of the same species have the same inherited traits but different acquired traits, such as what they have learned and skills they have developed. Only these different acquired traits can cause differences in each individual's chances of survival and reproduction.

The organisms have a variation in their genes. Those orgasms that share the same common ancestors have similarities in their genetic code, same anatomy, and the same emanate features.

As the life on earth took place some 4.5 billion years ago and since which the many organisms that evolved may possess the same genetic makeup that lead them to their evolution. There still exists interspecific variation and some have differences due to the mode of adaptation. Hence the statement is false.

Learn more about the organisms of the same species that have the same traits

brainly.com/question/12649119.

Formula of a copper (II)sulfate hydrate lab

Mass of empty dish: 50.58 g
mass of crystals and dish: 55.63
mass of crystals after first heating: 54.57
mass of crystals after second heating: 53.83
mass of crystals after 3rd heating: 53.74
then it asks for the mass of crystals in the evaporating dish. i said 50.58/55.63x100= 90.94(i’ve yet to round to significant figures) and i’m unsure as to whether or not this is the proper equation?? i get more questions on the crystals for the heating, and then it goes to ask: determine the mass of water evaporated from ye crystals during the heating. If you know what equation to use, please let me know!!

the other questions: using the mass of water evaporated from the crystals after the 3rd heating, determine the percentage by mass of water in the copper (II) sulfate hydrate crystals.

Based on the following formulae fir copper determine the GFM of the hydrate crystals: CuSO4 x 5H2O
then more like that but this ones for the accepted percentage by mass of water in the hydrate crystals: CuSO4x5H2O.

then determine percent error.

Answers

Answer:

Weigh the empty crucible, and then weigh into it between 2 g and 3 g of hydrated copper(II) sulphate. Record all weighings accurate to the nearest 0.01 g.

Support the crucible securely in the pipe-clay triangle on the tripod over the Bunsen burner.

Heat the crucible and contents, gently at first, over a medium Bunsen flame, so that the water of crystallisation is driven off steadily. The blue colour of the hydrated compound should gradually fade to the greyish-white of anhydrous copper(II) sulfate. Avoid over-heating, which may cause further decomposition, and stop heating immediately if the colour starts to blacken. If over-heated, toxic or corrosive fumes may be evolved. A total heating time of about 10 minutes should be enough.

Allow the crucible and contents to cool. The tongs may be used to move the hot crucible from the hot pipe-clay triangle onto the heat resistant mat where it should cool more rapidly.

Re-weigh the crucible and contents once cold.

Calculation:

Calculate the molar masses of H2O and CuSO4 (Relative atomic masses: H=1, O=16, S=32, Cu=64)

Calculate the mass of water driven off, and the mass of anhydrous copper(II) sulfate formed in your experiment

Calculate the number of moles of anhydrous copper(II) sulfate formed

Calculate the number of moles of water driven off

Calculate how many moles of water would have been driven off if 1 mole of anhydrous copper(II) sulfate had been formed

Write down the formula for hydrated copper(II) sulfate.

#*#*SHOW FULLSCREEN*#*#

Explanation:


3. A 240 mL sample of argon gas at 270 K is cooled until the volume is 180 mL. What is the new temperature?

Answers

Answer:

202.5 K

Explanation:

PLSS HELP! The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (4 points)
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.

Answers

Answer:

The answer is option A..

Hydrogen and oxygen are examples of which of these?
elements
compounds
none of the above
molecules
I need to know astroides

Answers

Molecules
I hope this helps

Help plzzzzz ASAP!!!!!!!!

Answers

1. NaF, Na₂S, Na₃P, Na₂O

2. MgF₂, MgS, Mg₃P₂, MgO

3. AlF₃, Al₂S₃, AlP, Al₂O₃

Further explanation

Given

Ionic charge

Required

The formula of binary ionic compounds

Solution

Ionic compounds consisting of cations (ions +) and anions (ions -)

Ionic compounds usually consist of metal cations and non-metal anions

Metal: cation, positively charged.

Nonmetal: negatively charged

The anion cation's charge is crossed

The ionic compounds :

1. NaF, Na₂S, Na₃P, Na₂O

2. MgF₂, MgS, Mg₃P₂, MgO

3. AlF₃, Al₂S₃, AlP, Al₂O₃

A sample of carbon dioxide gas at a pressure of 1.10 atm and a temperature of 20.6 C, occupies a volume of 19.2 L. If the gas is allowed to expand at a constant temperature to a volume of 24.3 L, the pressure of the gas sample will be ____ atm.

Answers

Answer:

P₂ = 0.87 atm

Explanation:

Given data:

Initial pressure = 1.10 atm

Initial volume = 19.2 L

Final volume = 24.3 L

Final pressure = ?

Solution:

The given problem will be solved through the Boyle's law,

"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"

Mathematical expression:

P₁V₁ = P₂V₂

P₁ = Initial pressure

V₁ = initial volume

P₂ = final pressure

V₂ = final volume  

Now we will put the values in formula,

P₁V₁ = P₂V₂

1.10 atm × 19.2 L = P₂ × 24.3 L

P₂ = 21.12 atm. L/ 24.3 L

P₂ = 0.87 atm

A 0.200 M NaOH solution was used to titrate a 18.25 mL HE
solution. The endpoint was reached after 31.20 mL of titrant
were added. Find the molar concentration of the original HF
solution.

Answers

Answer:

M₂ = 0.34 M

Explanation:

Given data:

Molarity of NaOH =M₁ =  0.200 M

Volume of HF =V₂=  18.25 mL

Volume of NaOH added = V₁ = 31.20 mL

Molarity of HF solution = M₂ = ?

Solution:

M₁V₁  =  M₂V₂

by putting values,

0.200 M × 31.20 mL = M₂ × 18.25 mL

M₂ = 0.200 M × 31.20 mL /  18.25 mL

M₂ = 6.24 M.mL / 18.25 mL

M₂ = 0.34 M

Please Help! Thank You

Answers

Answer:

61.5 dry quarts = 67.72509L

Explanation:

PLeaseeeeeee ANSWERRR

Answers

Answer: looks like A

Explanation:

Dry ice changes from a solid to a gas in a process known as A. Melting B. Freezing C.sublimation

Answers

Answer:

c

Explanation:

solid to gas directly

Question 2 (Multiple Choice Worth 2 points)
(01.03 LC)
2
A student is trying to calculate the density of a can. He already knows the mass, but he needs to determine the volume as well. Which of the following formulas can be used to calculate
the volume of the can?
3
O V =
3
1
OVE Tran
3
OV=53
Ov=mrah

Answers

Answer:

[tex]\pi[/tex] r²  x h

Explanation:

A can is cylindrical in nature. Using the formula of the volume of the can, we can find this unknown volume.

The volume of cylinder is given as:

   Volume of a cylinder  = Area x height

  Volume of  a cylinder = [tex]\pi[/tex] r²  x h

Therefore density of the can;

      Density  = [tex]\frac{mass}{volume}[/tex]

What three consumers live in the epipelagic zone?

Answers

Answer:

The epipelagic zone reaches from the surface of the ocean down to around 650 feet. This is the zone most exposed to light, and as such is host to the highest concentrations of the ocean's life. There are thousands of animals that roam this zone, including dolphins, most sharks, jellyfish, tuna and corals.

(From Internet I’m being honest)

Rearrange the elements in the order of increasing first ionization energy. Place the element symbol with the lowest first ionization energy at the top, and the element with the highest first ionization energy at the bottom. I Br F CI

Answers

Answer:

I,Br,Cl,F

Explanation:

ionization energy decreases the farther down an element is

If more of a liquid evaporates,does that mean it has stronger intermolecular forces

Answers

Answer:

No

Explanation:

The stronger the intermolecular forces the molecules tend to stay in the liquid phase. Compounds with weak intermolecular forces are more volatile and more molecules overcome those forces to pass to the gas phase.

According to kinetic theory, all matter is made up of small particles. The particles are constantly
moving
Diagram 1 shows how the particles may be arranged in a solid.
Diagram 1
(a)
One kilogram of a gas has a much larger volume than one kilogram of a solid
Use kinetic theory to explain why.
Enter your answer

Answers

Answer:

Explanation:

(a) there are strong forces (of attraction) between the particles in a solid

accept molecules / atoms for particles throughout

accept bonds for forces

1

(holding) the particles close together

particles in a solid are less spread out is insufficient

1

or

(holding) the particles in a fixed pattern / positions

but in a gas the forces between the particles are negligible

accept very small / zero for negligible

accept bonds for forces

1

so the particles spread out (to fill their container)

accept particles are not close together

gas particles are not in a fixed position is insufficient

One kilogram of a gas has a much larger volume than one kilogram of a solid. In kinetic theory particles in a solid are less spread out but in gas the force between the particles are negligible.

What is Kinetic Theory of matter ?

The kinetic theory of matter states that all matter is made up of tiny particles which are constantly moving in a state of motion. All particles should posses energy.

Thus from above conclusion we can say that One kilogram of a gas has a much larger volume than one kilogram of a solid. In kinetic theory particles in a solid are less spread out but in gas the force between the particles are negligible.

Learn more about the Kinetic theory of matter here: https://brainly.com/question/1948317

#SPJ2

Which of the following latitudes receive the most direct solar energy?
A latitudes near the north pole
B latitudes near the south pole
C latitudes near mountain ranges
D latitudes near the equator

Answers

Answer:

The answer to your question is D.

Explanation:

The latitudes near the equator receives the most direct solar energy.

Hope this helps :)

Which is an example of chemical change?

Answers

Answer:

Burning, cooking, rusting and rotting are examples of chemical changes.

15
Select the correct boxes.
Which two elements have the same number of valence electrons?
Element
Atomic Number
barium
56
neon
10
silicon
14
carbon
6
Reset
Reset
Next

Answers

Answer:

barium and silicon has same valence electrons

Explanation:

barium-2,8,18,18,8,2

neon-2,8

silicon-2,8,2,2

carbon-2,4

Answer: both barium and silicone

Explanation:

it was an my exam

Hydrochloric acid (HCl) and sodium hydroxide (NaOH) react to form water and sodium chloride (NaCl). If you have 2.87 g of HCl, 3.75 g of water, and 1.98 g of NaCl, how many grams of NaOH were reacted? Your answer should go to the hundredths place.

Answers

Answer:

2.86g

Explanation:

Mass of HCl  = 2.87g

Mass of water  = 3.75g

Mass of NaCl  = 1.98g

Unknown:

Mass of NaOH reacted  = ?

Solution:

  The reaction expression is given as:

           HCl    +   NaOH   →   NaCl   +  H₂O

According to the law of conservation of mass, the mass of reactants and products must be the same.

   Mass of HCl   +   Mass of NaOH  = Mass of NaCl  +  Mass of H₂O

      2.87g + Mass of NaOH  = 1.98g + 3.75g

           Mass of NaOH  = 1.98g + 3.75g - 2.87g  = 2.86g

please help! you are amazing! also brainliest :)

Which list is in order from biggest to smallest?

A. Universe - Galaxy - Solar system - Earth
B. Earth - Solar system - Nebula - Galaxy
C. Solar system - Galaxy - Nebula - Earth
D. Universe - Earth - Solar system - Nebula

Answers

im pretty sure its A if i did all my reasearch right.

hope this helps luv. <3

Answer:

is A

Explanation:

Universe - Galaxy - Solar system - Earth

Brainliest plz

Hope it work

The total number of the elements above with 2 valence electron is ____.

Answers

Answer:

four elements

Explanation:

He = 1s²

Be = 1s² 2s²

C = 1s² 2s² 2p²

Mg = 1s² 2s² 2p⁶ 3s²

Si = 1s² 2s² 2p⁶ 3s² 3p²

Ca = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

Valence electrons are those electrons which are present in outer most electronic shell.

He, Be, Mg, Ca these four elements have 2 valence electrons.

While Si and C have four valance electrons.

The total number of the elements above with 2 valence electron is four.

The electronic configurations of the elements are given:

He = 1s²

Be = 1s² 2s²

C = 1s² 2s² 2p²

Mg = 1s² 2s² 2p⁶ 3s²

Si = 1s² 2s² 2p⁶ 3s² 3p²

Ca = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

Valence electrons are those electrons which are present in outer most electronic shell.

He, Be, Mg, Ca these four elements have 2 valence electrons.

Learn more:

brainly.com/question/16089134

Calculate the molar mass for oxygen gas

Answers

For example, the atomic mass of an oxygen atom is 16.00 amu; that means the molar mass of an oxygen atom is 16.00 g/mol. Further, if you have 16.00 grams of oxygen atoms, you know from the definition of a mole that your sample contains 6.022 x 10^23 oxygen atoms.

need help with physical changes

Answers

Answer:

I give u three in explanation

Explanation:

Crushing the can, stomping on the can, and squishing the can

During ionic bonding, there must be a chemical interaction between...

O metallic elements, only

O nonmetallic elements, only

O one metallic and one nonmetallic element, only

O metalloids ,only

Answers

one metallic and one nonmetallic element, only.

What type of energy is caused by positive and negative charges in matter

Answers

Answer:

Static electricity is the result of an imbalance between negative and positive charges in an object. These charges can build up on the surface of an object until they find a way to be released or discharged.

Explanation:

I’m pretty sure it’s static electricity

One glass of water is 85 degrees F and another is 40 degrees F. When an Alka Seltzer tablet is dropped into each glass, at the same time, which of the following describes the expected results? The 85 degree F glass will have an accelerated chemical reaction, because the water was warmer.

The 85 degree F glass will have an accelerated chemical reaction, because the water is cooler.

The 40 degree F glass will have an accelerated chemical reaction, because the water is cooler.

The 40 degree F glass will have an accelerated chemical reaction, because the water was warmer.

Answers

Answer:

The 85 degree F glass will have an accelerated chemical reaction, because the water was warmer.

Explanation:

The glass of water with the higher temperature will have an accelerated chemical reaction because the water is warmer.

The rate of chemical reaction is directly proportional to the temperature changes.

As temperature increases so is the reaction rate.

Temperature is directly proportional to the average kinetic energy of reacting particles. So, the glass water at a higher temperature will have a faster reaction. The elevated temperature ensures increase in frequency of colliding particles in the reaction.

Helga has a box. She wants to determine how much the box can hold. Which measurement should she calculate?

A) Length
B) Area
C) Volume
D) Perimeter

Answers

C) volume

Explanation:

hope it helps !

Answer:

Volume. "How much the box can hold" means how much matter can fit into the box

What does the slope of a distance versus time graph represent?

Total time
Average time
Average distance
Speed

Answers

Answer:

Speed

Explanation:

Motion can be represented by a distance-time graph, which plots distance on the y-axis and time on the x-axis. The slope of a distance-time graph represents speed. The steeper the slope is, the faster the speed.

Hope this helps!:)

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