Helppppppppppp it’s due today pls help and thanks

Answer:

21

Explanation:

2 + 2 = 21

Answer:

A. Thin

Explanation:

i took the test a while back yw <3

Answer:

Final temperature  = 83.1 °C

Explanation:

Given data:

Mass of concrete = 25 g

Specific heat capacity = 0.210 cal/g. °C

Initial temperature = 25°C

Calories gain = 305 cal

Final temperature = ?

Solution:

Q = m. c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = T2 - T1

305 cal = 25 g ×0.210 cal/g.°C × T2 -  25°C

305 cal = 5.25cal/°C × T2 -  25°C

305 cal / 5.25cal/°C = T2 -  25°C

58.1 °C = T2 -  25°C

T2 = 58.1 °C + 25°C

T2 = 83.1 °C

Answer:

6.75 moles of CuCl₂ were used

Explanation:

Given data:

Number of moles of AlCl₃ formed = 4.5 mol

Number of moles of CuCl₂ used = ?

Solution:

Chemical equation:

3CuCl₂ + 2Al  →   2AlCl₃ + 3Cu

Now we will compare the moles of CuCl₂ and AlCl₃

               AlCl₃       :      CuCl₂

                   2         :        3

                 4.5        :      3/2×4.5 = 6.75

6.75 moles of CuCl₂ were used.

Answer:

lol thanks

Explanation:

Answer:

Explanation:

thxxxssss

Answer:

c

Explanation:

please give me brainliest

Answer:

the history of life in the geologic past is the correct answer

Explanation:

If you still need help, the answer is the history of life in the geologic past. I just did this test and got that question correct :) have a nice day!

Answer:

2.51 x 1023 atoms C

Explanation:

MW C = 12.011

5g x (1mol/12.011g) =0.416 mol

0.416 mol x (6.022x10^23) = 2.51 x 1023 atoms C

Mass of Ca(OH)2= 46.916 g

Given

Reaction

CaO + H2O - Ca(OH)2

Required

mass of Ca(OH)2

Solution

Mol of CaO :

= mass : MW

= 35.5 g : 56 g/mol

= 0.634

From the equation , mol ratio CaO : Ca(OH)2 = 1 : 1, so mol Ca(OH)2 = 0.634

Mass Ca(OH)2 :

= mol x MW

= 0.634 x 74

= 46.916 g

The volume of a sample of ammonia gas : 5.152 L

Given

0.23 moles of ammonia

Required

The volume of a sample

Solution

Assumed on STP

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol.

So for 0.23 moles :

= 0.23 x 22.4 L

= 5.152 L

Answer:

i think a as well but not sure

Explanation:

Answer:

I believe it is B

Explanation:

Answer:

nitric acid anhydride

OR

Dinitrogen pentaoxide

The name of N4O10 is Tetranitrogen decaoxide.

In order to name this compound, we have to consider the number of atoms of each element in the compound.

Looking at the compound, we can see that there are four nitrogen and ten oxygen atoms. Nitrogen is an element in group 15 of the periodic table and has five valence electrons. Oxygen is an element in group 16 of the periodic table and has six valence electrons. These two elements combine to give tetranitrogen decaoxide (N4O10).

Hence, the accurate name of the compound is tetranitrogen decaoxide.

Learn more: https://brainly.com/question/1388366

Answer:

1. is atmosphere

2. is air pressure

3. green house gases

4a. nitrogen

4b. oxygen

4c. carbon dioxide

5. stratosphere

6. troposphere

7. Air pressure is higher at lower altitudes. Air density is higher at lower altitudes. There is more space between air molecules at higher altitudes. There is less oxygen to breathe at the top of a high mountain than there is at sea level.

8. exosphere, this is because the air is thin, therefore making it cold

9. Without this barrier in place, all of the radiation would reach Earth, which is very damaging to plants and us.

10. Temperature increases as you gain altitude in the stratosphere and the thermosphere. Temperature decreases as you gain altitude in the troposphere and mesosphere.

11. When the level of greenhouse gases increase, the concentration of gases in the atmosphere would become greater. This event allows the gas molecules to increase in number, As a result, the air temperature increases.

note: 12 and 13 you are going to have to workout for yourself as I have no clue lol-

hope this helps :)

Answer:

2.55 moles of NaOH are needed react with 500.0 gram of H₂SO₄.

Explanation:

Given data:

Mass of H₂SO₄ = 500.0 g

Number of moles of NaOH needed = ?

Solution:

H₂SO₄ + 2NaOH  → Na₂SO₄ + 2H₂O

Number of moles of H₂SO₄:

Number of moles = mass/molar mass

Number of moles = 500.0 g/ 98.07 g/mol

Number of moles = 5.09 mol

Now we will compare the moles of H₂SO₄ and NaOH.

                     H₂SO₄         :           NaOH

                           1             :               2

                         5.09         :            1/2×5.09 = 2.55 mol

Thus, 2.55 moles of NaOH are needed react with 500.0 gram of H₂SO₄.

The number of mole of NaOH required to react with 500 g of H₂SO₄ is 10.2 moles

We'll begin by calculating the number of mole of in 500 g of H₂SO₄

Mole = mass / molar mass

Mole of H₂SO₄ = 500 / 98

Mole of H₂SO₄ = 5.1 moles

Finally, we shall determine the mole of NaOH required for the reaction.

H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

From the balanced equation above,

1 mole of H₂SO₄ required 2 moles of NaOH.

Therefore,

5.1 moles of H₂SO₄ will require = 5.1 × 2 = 10.2 moles of NaOH

Thus, 10.2 moles of NaOH is required for the reaction

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Answer: 0.1612 kilometers

Explanation:

Answer:

Larger

Loses, positive

gains, negative

Explanation:

5. Before becoming ions, the sodium atom is larger than the chlorine atom. This is because, generally metals have a greater atomic radius compared to non - metals.

Also, as one moves from left to right across the period, the atomic radius reduces.

Chlorine is to right on the periodic table and Sodium is to the left.

6/7;

When a neutral atom gains electrons, it becomes negatively charged. This is because the number of electrons in the atom becomes more than the number of protons.

This is the case with the sodium. As it loses electrons, it becomes positively charged.

The reverse is the case when chlorine gains electrons to become negatively charged.

Answer:

The cake is rising and cooking

Explanation and Answer:

This is an opinion based question and there could be many different responses these are just examples of solution to restore the fishery:

-limiting the season during which lobsters can be caught this allows the population to reproduce itself gradually but maintaining it in control

-limiting the amount of lobster that can be caught therefore again letting the population increase

Answer:

A) 250 ml

Explanation:

Vcyl= π • r2 • h -----> Vcyl= π· 0.9^2 · 6=  15.2681402964464 x 16.4 millimetres = 250.3975008617209 rounded off to 250 millimetres :)

Answer:

the answer is A

Explanation:

I took the test

Salinity of water is the total concentration of the salts present in unit volume of water. Ocean water in regions with high levels of precipitation has higher salinity. Hence option c is correct.

The salinity of sea water is expressed as a salt (in g) to liter of water ratio. Each liter of sea water contains around 35 grams of dissolved salts. It is spelled 35. The usual range of ocean salinity is 33-37 g/L.

There is a lot of rain in some places of the ocean. Freshwater poured to the surface dilutes the seawater, reduces salinity, and hence makes the seawater less dense. Near land, where rivers provide freshwater, seawater may be less saline.

The seawater near Antarctica has a low salinity of little about 34 ppt, and it is as low as 30 ppt in some spots around the Arctic. Regions where, the precipitation is higher have higher salinity in oceans.

Find more on salinity :

https://brainly.com/question/14575146

#SPJ6

Answer:

Average atomic mass = 6.94 amu.

Explanation:

Given data:

Average atomic mass = ?

Atomic mass of first isotope = 6.017 amu

Atomic mas off second isotope = 7.018 amu

Abundance of fist isotope = 7.30%

Abundance of second isotope = 92.70%

Solution:

Average atomic mass  = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass  = (7.30×6.017)+(92.70×7.018) /100

Average atomic mass =  43.924 + 650.57 / 100

Average atomic mass  = 694.494 / 100

Average atomic mass = 6.94 amu.

The average atomic mass is 6.94 amu.

The Atomic mass of the first isotope = 6.017 amu

Atomic mas off second isotope = 7.018 amu

The abundance of first isotope = 7.30%

The abundance of second isotope = 92.70%

Average atomic mass  = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

= (7.30×6.017)+(92.70×7.018) /100

=  43.924 + 650.57 / 100

= 694.494 / 100

= 6.94 amu.

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The volume of Oxygen : 20,000 L

Given

400 L : initial volume

150 atm  : initial pressure

3 atm : final pressure

Required

Final volume

Solution

Boyle's Law  

At a fixed temperature, the gas volume is inversely proportional to the pressure applied  

[tex]\rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]

Input the value :

V₂ = (P₁V₁)/P₂

V₂ = 150 atm x 400 L / 3 atm

V₂ = 20,000 L

Answer:

C. Carbon

Explanation:

Carbon has an electronegativity of 2.55, followed by Tin at 1.96, Silicon at 1.90 and the least electronegative would be Lead at 1.87.

Answer:

The Ionic compound is held by ionic bonding and this ionic bond forms between a metal and a non-metal. Here the calcium atom is the metal and the oxygen atom is a non-metal this set of atoms will form an ionic compound.

Answer:

Answer: Plastics, in particular, contain mainly carbon and hydrogen, with similar energy content to conventional fuels such as diesel. ... It's possible to convert all plastics directly into useful forms of energy and chemicals for industry, using a process called “cold plasma pyrolysis”.

Explanation:

The number of moles : n = 4.95 x 10 ²⁴

Given

2.98E28 molecules of water

Required

The number of moles

Solution

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

n = N : No

n = 2.98 x 10²⁸ : 6.02.10²³

n = 4.95 x 10 ²⁴