Plz help me I am timed!!

Answers

Answer 1

Answer:

What do you need help with

Explanation:

Answer 2

Explanation:

okay I'll help but whats the question


Related Questions

what is one property of skim milk indicating that it is a colloidal dispersion?​

Answers

Answer:

it's dairy

Explanation

Help me! Who ever gets to answer and has the best answer gets brainliest (very easy!)

Answers

Fire-3
Decay-1
Earth-2

Answer:

Fires --> These consume fuel and convert chemical energy stored in that fuel into thermal light and sound energy.

Decay -->The breakdown of dead plants and animals releases thermal energy.

Earth --> Thermal energy comes from deep inside and it is called geothermal energy.

Help me! Who ever gets to answer and has the best answer gets brainliest

Answers

Answer:

Decay-the breakdown of dead plants..

Earth- thermal energy comes from deep inside...

Fires- these consume feul...

Explanation:

Answer:

Fires - These consume fuel and covert chemical energy stored in that fuel into thermal, light and sound energy

Decay - The breakdown of dead plants and animals produces thermal energy

Earth - Thermal energy comes from deep inside and is called geothermal energy

Explanation:

Fires, when you burn wood, you convert chemical energy from the wood into thermal (warmth from the fire), light (glow from the fire), sound (crackling sound of wood burning)

Decay - I can't explain that one to you but there are power plants that use decomposition to produce energy

Earth - Beneath the crust there is the mantle, which consists of molten rock which produces a lot of thermal energy. This can be seen in geysers, where the molten rock heats water and hot water can burst out of the surface. Applies to hot springs too

A 250mL beaker is submerged in a large container of Liquid A and turned upside down, and another 250mL beaker is submerged and turned upside down in a large container of Liquid B. Hydrogen H2 gas is bubbled into each upside-down beaker until 100mL of liquid has been displaced. The masses mA and mB of hydrogen inside each beaker is then chemically determined. Note for advanced students: you may assume the solubility of H2 in either liquid is very low.

a. mx will be greater than my
b. mx will be less than my
c. mx will be equal to my
d. It's impossible to predict whether mx or my will be greater without more information.

Answers

Answer:

Mx will be less than My.

Explanation:

The correct option is - Mx will be less than My.

Because, liquid X have been higher viscosity and vapor pressure than liquid B.

Vapor pressure of liquid A is greater, so the amount of liquid X will vaporized greater and H2 gas has been displaced greater from the beaker as compared to liquid Y.

The amount of H2 in liquid Y remains greater in beaker as compared to liquid X.

So, Mx will be less than My.

You have to prepare a pH 5.00 buffer, and you have the following 0.10 M solutions available: HCOOH (pka=3.74), HCOONa, CH3COOH (pka=4.74), CH3COONa, HCN (pka=9.31), and NaCN. Which solutions would you use?

Answers

Answer:

CH3COOH - CH3COONa since its pKa is closest to the required pH.

Explanation:

Hello there!

In this case, in agreement with the theory of buffers as solutions able to withstand severe pH changes due to the addition of acidic or basic substances, it is possible to set up a generation equilibrium expression for the acids herein given:

[tex]Ka=\frac{[A^-][H_3O^+]}{[HA]}[/tex]

Which leads to the Henderson-Hasselbach equation:

[tex]pH=pKa+log(\frac{[A^-]}{[HA]} )[/tex]

Thus, since all the buffers have [A-]=[HA]=0.10M, the log part becomes 0 and therefore the best buffer will have the closest pKa to the required pH, which is CH3COOH - CH3COONa since its pKa is 4.74.

Best regards!

[tex]CH_3COOH\; and\; CH_3COONa[/tex] can be used to prepare a pH buffer, if 0.10 M solution available of the solutions.

What is buffer?

Buffer is a solution, that resist change in pH, by adding or removing H+ ions to the solution.

Maintaining a constant pH is necessary to complete many reactions.

In blood, bicarbonates maintain the pH of the body.

[tex]CH_3COOH\; and\; CH_3COONa[/tex] have approx the nearest pH, so they can be used to make a buffer.

Thus, the correct options are [tex]CH_3COOH\; and\; CH_3COONa[/tex]

Learn more about buffer

https://brainly.com/question/24188850

What is mass times acceleration equal to?

Answers

Answer:

Mass (kg) × Acceleration (m/s²) = Force (N)

Newton's second law of motion is F = ma, or force is equal to mass times acceleration.

2. A chemical's flash point is the​

Answers

Flash point is the minimum temperature at which a liquid forms a vapor above its surface in sufficient concentration that it can be ignited.

- Rachel performed an investigation to study the thermal conductivity of four different materials. She started with four identically shaped rods—each made of a different material. Then, she placed one end of each rod into a pot of boiling water, which was at 100°C.

- After five minutes, Rachel measured the temperatures of the ends of the rods that were sticking up out of the pot to see whether they got hot. Her results are shown below.

Thermal Conductivity Investigation
Material Temperature of End of Rod After 5 Minutes
Material 1 41°C
Material 2 53°C
Material 3 98°C
Material 4 59°C

- Rachel knows that one of the materials is copper and that copper conducts thermal energy very well. Which of the materials is most likely copper?


A.
material 1
B.
material 3
C.
material 4
D.
material 2

Answers

Answer:

I will have the maths book

Answer:98

Explanation:

If a compressed air cylinder for scuba diving contains 6.0 L of gas at 18°C and 200 atm pressure, what volume does the gas occupy at 1.0 atm and 25°C?​

Answers

Answer:

[tex]V_2=1228.9L[/tex]

Explanation:

Hello there!

In this case, given the pressure, temperature and volume of the gas, we notice that we need the combined ideal gas as shown below:

[tex]\frac{P_2V_2}{T_2} =\frac{P_1V_1}{T_1}[/tex]

Thus, solving for the final volume, V2,  we would obtain:

[tex]V_2=\frac{P_1V_1T_2}{T_1P_2}[/tex]

Now, we plug in the data and make sure the temperature must be in Kelvins to obtain:

[tex]V_2=\frac{200atm*6.0L*(25+273)K}{(18+273.15)K(1.0atm)}\\\\V_2=1228.9L[/tex]

Best regards!

A reaction has a theoretical yield of 27.6 g. When the reaction is carried out, 13.4 g of the product is obtained. What is the percent yield?

A) 48.6 %
B) 206 %
C) 370 %
D) 64.7 %

Answers

I believe it’s A

13.4 is 48.6% of 27.6

Answer:

yee I'm excellent in maths and science

For each of the environments below: (1) identify your system and surroundings and (2) predict whether it would be endothermic or exothermic.a.Wood burningSystem:Surroundings:Enthalpy Change:b.Water freezingSystem:Surroundings:Enthalpy Change:c.Sweat evaporatingSystem:Surroundings:Enthalpy Change:d.Chemical hand-warmerSystem:Surroundings:Enthalpy Change:

Answers

Answer:

A) Wood burning

system : Wood.

surroundings : atmosphere

Enthalpy : Exothermic

B) Water Freezing system

System : Refrigerator

surroundings :  water in the refrigerator

enthalpy change : Endothermic

C) Sweat evaporating

System :  Human being

surroundings : Air nearby

Enthalpy change : exothermic

D) Chemical Hand-warmer

system : Hand warmer pack

Surroundings : human palms

Enthalpy Change : Exothermic

Explanation:

A) Wood burning

system : Wood

surroundings : atmosphere

Enthalpy : Exothermic

This system give away energy to its surroundings hence its enthalpy change is exothermic

B) Water Freezing system

System : Refrigerator

surroundings :  water in the refrigerator

enthalpy change : Endothermic

The system absorbs heat from what is put inside(surroundings ) of it hence this is na endothermic system

C) Sweat evaporating

System :  Human being

surroundings : Air nearby

Enthalpy change : exothermic

This is an exothermic reaction ( enthalpy change ) because the system gives out heat to the surrounding

D) Chemical Hand-warmer

system : Hand warmer pack

Surroundings : human palms

Enthalpy Change : Exothermic

There is movement of heat from the system to the surrounding hence it is an exothermic reaction

6. Menthol is a member of the terpene family of natural products. It exists in a (1R, 2S, 5R) form and a (IS, 2R, 5S) form. Are these two compounds enantiomers or diastereomers?
​​

Answers

Here ya go if you need the link we’re I found this answer key https://studylib.net/doc/8708211/exam-2---chemistry

Which substance is soluble in water?

Answers

Things like salt, sugar and coffee dissolve in water. They are soluble. They usually dissolve faster and better in warm or hot water. Pepper and sand are insoluble, they will not dissolve even in hot water.

What is the hydronium ion concentration of a solution whose pH is 4.12?
a. 5.1 x 10–6 M
b. 7.6 x 10–5 M
c. 6.4 x 10–5 M
d. 4.4 x 10–8 M

Answers

A is may be the correct answer

Which describes bonding electrons in a polar covalent bond?


electrons that are not shared equally

electrons that are shared in diatomic molecules

electrons that are shared equally

Answers

Answer:

I think the third one

Explanation:

i think

Answer:

electrons that are NOT shared equally

Explanation:

Formula mass of Ca(NO2)2

Answers

Answer: 132.1 g/mol

Explanation: 40.08 + 2·(14.01+2·16)

Calculate the pH of a 0.10 M NH4Cl solution.

Answers

Answer:

Answer: pH = 2.72

Explanation:

Calculate the pH of 0.010 M HNO2 solution. The K, for HNO2 is 4.6 x 104 

Reactants for a certain reaction are combined in a solution. Which solution
would have the most successful collisions and so enable the reaction to
proceed quickly?
A. A solution at low concentration and low temperature
B. A solution at high concentration and low temperature
O C. A solution at high concentration and high temperature
D. A solution at low concentration and high temperature

Answers

The correct answer is solution B!

What would happen to the position of the equilibrium when the following changes are made to the reaction below?
2HgO(s) ↔ Hg(l) + O2(g)

1.) The pressure on the system decreases.

Answers

Any impact on pressure will only affect gas molecules. So in this question the reactant has 0 gas molecules and the products have 1 gas molecule (the O2 molecule).

This means when you decrease the pressure the equilibrium will shift in order to oppose this change.

As you decreased the pressure it will move to the reaction that will increase the pressure back to equilibrium. So if you decrease pressure the equilibrium will shift to the right hand side (forward reaction) to oppose the change in pressure and a higher yield of Hg(l) and O2(g) will be produced.

The gases are contained in a reaction vessel and are in equilibrium at 298 K

X2Zi â 2XZ2(g)


a. Activation energy
b. Total mass of the system
c. Molar concentration of XZ4(g)
d. Number of molecules present
e. Equilibrium constant

1. Is decreased by the addition of a catalyst?
2. Is decreased when the volume of the reaction vessel is increased and equilibrium is reestablished at 298 K?

Answers

Answer:

1) Activation energy  ( A )

2) Molar concentration of X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) ( C )

Explanation:

X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) ⇄ 2XZ

1) Activation energy Is decreased by the addition of a catalyst

while Equilibrium constant will Increase and other options will still remain unaffected

2)Molar concentration of X[tex]_{2}[/tex]Z[tex]_{4}[/tex](g) Is deceased when the volume of the reaction vessel is increased and equilibrium is reestablished at 298 K

while Number of molecules present will Increase

How do chemists count the number of representative particles in a substance?

Answers

The mole allows chemists to count the number of representative particles

In what form metals are found in nature

Answers

Answer:

Metals in nature are found in rock form, mineral forms etc..

Answer:

Metals are found in rock

.....plllzzz heeelp me fast?? ​

Answers

Answer:

Explanation:

It is 11

It’s 11 dndndnenddnnenrfjdnnrfnnd

Which statement defines enzymatic activity? Enzymes are required to slow down biological reactions within cells. Specific enzymes can catalyze a wide variety of chemical reactions. Enzymes regulate cellular functions through feedback mechanisms. Enzymes bind substrates so that reactive groups have many different orientations.

Answers

Answer:

Enzymes are required to slow down biological reactions within cells,

this could be not sure

Answer:

D

Explanation:

Enzymes bind substrates so that reactive groups have many different orientations.

A student is heating a crystal of alum to
determine the hydrate formula. If she removes
it from the heat before all the water has been
removed, what will happen to the calculated
hydrate formula?
A. It will not be affected by the error.
B. The mole ratio will indicate less water than was
actually present.
C. The mole ratio Will indicate less alum than was
actually present.

Answers

I think It’s probably a

A gas goes from 1L at 273 K to 2 L when heated. What is the new temp?

Answers

Answer:

Given : Diatomic molecule at 273K

'q' absorbed = positive = +100Cal = 100 x 4.184J = 418.4J

'W' done by system = negative = -209J

By first law of thermodynamics;

ΔU = q + W = 418.4 + (-209) = 209.4J

We know for diatomic molecule Cv=25R and CvΔT=ΔU

CvΔT=209.4

 25RΔT=209.4

ΔT=5R209.4×2

And, Heat exchange=Cm×ΔT 

where; Cm is molar heat capacity

Cm=ΔTHeat Exchange

substituting values for Heat Exchange = 418.4 and ΔT=5R209.4×2

Cm=5R

29. Which is the electron configuration of an atom
in the excited state?
(1) 1s 2s²2p2
(2) 1s 2s22p'
(3) 1s 2s22p5352
(4) 1s²2s²2p%35'

Answers

2 is right am 70 percent sure

how many grams of silver chloride are produced from 15.0 g of silver nitrate​

Answers

Answer:

4.2 g

Explanation:

Chlorofluorocarbons may be harming the ozone layer by ____.
a.
adding more ozone molecules
c.
destroying ozone molecules
b.
blocking ultraviolet radiation
d.
adding carbon dioxide molecules


Please select the best answer from the choices provided

Answers

Answer:

The awnser is C. Hope that helps!!!

2Na(s) + Cl2(g) - 2NaCl(s) + 822 kj

Answers

Answer:

Is there any other part to this question? If not I'm pretty sure the answer is 205.5 kJ

Explanation:

Answer:

822 kJ; 411 kJ/mol.

Explanation:

A chemist measures the enthalpy change during the following reaction: ()()()Use this information to complete the table below. Round each of your answers to the nearest kJ/mol. 1. ()()()Solution:  given reaction is 2Na + Cl2 --> 2NaCl         delta H = -822 KJ 1) 1/2Na + 1/4Cl2 --> 1/2NaCl divide the coficiant of given.

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