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Answer:

1 mole of zinc has 6.023 x 1023 atoms

So, 4.1 moles will have 4.1 x 6.023 x 1023 atoms = 24.694 x 1023 atoms

Explanation:

Answer:

Cretaceous Period

Explanation:

Dinosaurs went extinct about 65 million years ago (at the end of the Cretaceous Period), after living on Earth for about 165 million years.

Answer:

A plant cell has a cell wall but an animal cell dosnt have one

Explanation:

Brainliest plz

Explanation:

the cell wall surrounds the plasma membrane of the plant and provides tensile strength and protection against mechanical

Answer:

If im correct it’s radioisotope

Explanation:

Scientists often look at how much of isotopes of : Carbon-14  have decayed

To determine the age of fossils archeologist make use of the carbon-14 dating ( i.e. making use of naturally occurring radioisotope ¹⁴C ) which is used to determine the age of fossils or material that were once in living on earth.

Carbon has about three (3) isotopes ( Carbon-12, Carbon-13 and Carbon-14 ) .but Carbon-14 isotope is most useful in determining the age of fossils and once-living things

Hence we can conclude that scientists often look at how much of isotopes of Carbon-14 have decayed to help estimate the age of fossils.

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Answer:

The new temperature will be 565.83 K.

Explanation:

Gay Lussac's law establishes the relationship between the temperature and the pressure of a gas when the volume is constant. This law says that the pressure of the gas is directly proportional to its temperature. This means that if the temperature increases, the pressure will increase; or if the temperature decreases, the pressure will decrease.

In other words, Gay-Lussac's law states that when a gas undergoes a constant volume transformation, the ratio of the pressure exerted by the gas temperature remains constant:

[tex]\frac{P}{T} =k[/tex]

When an ideal gas goes from a state 1 to a state 2, it is true:

[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]

In this case:

Replacing:

[tex]\frac{180 kPa}{291 K} =\frac{350 kPa}{T2}[/tex]

Solving:

[tex]T2=350 kPa*\frac{291 K}{180 kPa}[/tex]

T2= 565.83 K

The new temperature will be 565.83 K.

Answer:

photosynthesis  are ligt water and carbon dioxide

Explanation:

Plants make their own food out of inorganic compounds through a process called photosynthesis that takes place in the leaves. The ingredients necessary for photosynthesis are light, water and carbon dioxide.

Answer:

z3 xCo2 + 75 = s01 + h20 = Z2

Explanation:

The study of chemicals is called chemistry.

The correct answer is A.

A combination reaction is defined as the joining of two different elements to form a new compound is called a combination reaction. A new compound is always formed in the reaction.

According to the question, in option A the [tex]Li_2Co_3[/tex] is formed and in reaction 4 [tex]H_2So_4[/tex] is formed.

Hence, the correct option is A that is Z1 and Z4.

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Answer:

C) It is the reactant that is left over after the reaction stops.

Explanation:

The excess reactant is the reactant that is left over after the reaction stops. The extent of the reaction is not determined by this reactant.

A limiting reactant is a reactant that is in short supply within a given reaction.

Such reactants determines the extent of chemical reaction.

Answer: C) It is the reactant that is left over after the reaction stops.

Explanation:

Hello, 3Coli Here!

Your Answer is Here:

I would recheck, redo, and revise my answers, if necessary. Also, I can look at the lesson again, if I forgot something. So that's what I would do.

Hopefully, this helps!

Ask your question below!

Answer:

I will just revise and check my answer, or I can redo the lesson.

Explanation:

Have a good day! :D

Answer:

36°C

Explanation:

Given parameters:

Mass of aluminum = 725g

Quantity of heat  = 2.35 x 10⁴J

Unknown:

Temperature change  = ?

Solution:

To solve this problem, we simply use the expression below:

  The quantity of energy is given as:

          Q  = m C Δt

Q is the quantity of energy

m is the mass

C is the specific heat capacity of aluminum  = 0.9J/g°C

Δt is the change in temperature

  The unknown is Δt;

             Δt  = [tex]\frac{Q}{mc}[/tex]    = [tex]\frac{2.35 x 10^{4} }{725 x 0.9}[/tex]    = 36°C

Answer:

B or D

Explanation:

.....I'm pretty sure I earned on some kids tv show

Answer:

The new concentration of the solution is;

0.01 M

Explanation:

The question relates to concentration of solution and proportion of mixtures

The given parameters are;

The volume of water added to the 0.1 M solution = 900 mL

The initial volume of the solution to which water was added = 100 mL

Therefore, the total final volume of the solution = 100 mL + 900 mL = 1000 mL = 1 L

The concentration of the solution = 0.1 M

The number of moles present in the solution, 'n', is given as follows;

n = 100 mL/(1000 mL) × 0.1 M = 0.01 moles

Given that no more concentrated solution was added, we have;

The number of moles in the 100 mL solution   = The number of moles in the 1,000 mL solution

Therefore, the number of moles in the 1,000 mL (1 L) solution = 0.01 moles

Therefore;

The new concentration of the 1,000 mL (1 L) solution = 0.01 moles/(1,000 mL) = 0.01 moles/(1 L) = 0.01 M (By definition of the molarity of a solution)

The new concentration of the 1,000 mL (1 L) solution = 0.01 M.

D. 0.01 M

Given:

The volume of water added to the 0.1 M solution = 900 mL

The initial volume of the solution to which water was added = 100 mL

So,

The total final volume of the solution = 100 mL + 900 mL = 1000 mL = 1 L

The concentration of the solution = 0.1 M

Firstly we need to find the number of moles which is represented by 'n':

 [tex]n = \frac{100mL}{1000mL}* 0.1 M\\\\n = 0.01 \text{moles}[/tex]

 The number of moles in the 100 mL solution   = The number of moles in the 1,000 mL solution

Thus,

The number of moles in the 1,000 mL (1 L) solution = 0.01 moles  

For calculation of new concentration:

Using Molarity formula:

The new concentration of the 1,000 mL (1 L) solution [tex]= \frac{0.01\text{ moles}}{1000mL} = \frac{0.01\text{ moles}}{1L} = 0.01 M[/tex]

The new concentration of the 1,000 mL (1 L) solution = 0.01 M.

Thus, the correct option is D.

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Which among the following will make lime water look milky

option C) Ca(OH)₂

Answer:

C.)He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.

Explanation:

From the analogy of the problem presented, we can see that Henry is grossly incorrect. His conclusion from the process of the experiment he carried out is completely wrong.

Physical changes are changes that alters the physical properties of matter particularly the form and state.

Chemical changes leads to the formation of a new kind of matter.

 We can see that since the salt was obtained back after evaporation, no change has occurred to it.

Therefore, evaporation in itself is a physical change process.

Answer:

c on ed

Explanation:

Answer:650K

Explanation:

Answer: 650K (1.45/145 = 6.50/x)

Explanation:

Answer:

a

Explanation:

Answer:

B. 11.18 mols of Cu

Explanation:

Given parameters:

Number of particles in Cu  = 6.73 x 10²⁴ particles

Unknown:

Number of moles  = ?

Solution:

A mole of a substance is known to contain the Avogadro's number of particles. To solve this problem;

          6.02 x 10²³ particles is contained in 1 mole of a substance

         6.73 x 10²⁴ particles  will be contained in [tex]\frac{6.73 x 10^{24} }{6.02 x 10^{23} }[/tex]   = 11.18moles of Cu

Explanation:

Purpose and Theory: A tablet of vitamin C contains the active ingredient called ascorbic acid (HC,H,0.).

Ascorbic acid is an organic acid which is a white power and is soluble in water.

In the following microtitration lab you will be grinding up a vitamin C tablet

, and using a 0.10 g sample of the

vitamin C powder, which will be dissolved in 20-40 mL of water. This solution will be used to determine the

quantity of ascorbic acid in a commercial vitamin C tablet.

Groups

Lab 2

# of Drops 1 or Drops 2 of Drops 3

96

91

94

Hadia

Data & Analysis:

Complete the missing information in the following data table [24]

1

2

3

Trial

Volume of NaOH (drops)

0 05mL drop

(NaOH (O 0050mol/L)

Volume of NaOH (ML)

Average Volume of NaOH (ml)

T I

O 0050

00050

00050

The balanced chemical reaction between ascorbic acid and sodium hydroxide is:

HC,H,O + NaOH NaC,H,Oye H,O,

1. Stoichiometrically calculate the mass (in grams) of ascorbic acid in the powdered sample. 

Answer:

31g

Explanation:

80g(Ca)+m(H2O)=114g(CaOH)+2g(H2)

the total mass of the prodicts doesn't change throughout the process

80g+m(H20)=116g

m(H20)=31g

Answer:

The emptiest one.

Explanation:

The more water, the more heat molucules have to turn to boil.

Have a great day!

Hope I helped and it would be greatly appreciated if you could be considerate and give brainliest.

Answer:

In first mcq correct option is "solid"  while in 2nd correct is "gas"

Explanation:

Answer:

Filtration is the answer

Answer: So to figure out your energy balance you need to gather some important information.  That is, you eat more calories than your body uses. A kilojoule is a calorie) is a measure of energy in food. On average, people eat and drink around 8700 kilojoules a day.

Explanation: I hope that helped- Please mark me as brainliest!

don't know sorry.........

Answer:

Explanation:

The trick here is to realize that if you know the volume of a gas at STP, you can use the fact that

1

mole of any ideal gas occupies

22.7 L

under STP conditions to calculate how many moles of gas you have in your sample.

Under STP conditions:

1 mole of an ideal gas = 22.7 L

−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

In your case, you know that your sample of gas occupies

2.28 L

under STP conditions, which are currently defined as a pressure of

100 kPa

and a temperature of

0

∘

C

.

This means that your sample will contain

2.28

L

⋅

molar volume of a gas at STP



1 mole gas

22.7

L

=

0.10044 moles gas

Now, the molar mass of the gas is the mass of exactly

1

mole of the gas. In your case, you know that you get

3.78 g

for every

0.10044

moles, which means that you have

1

mole

⋅

3.78 g

0.10044

moles

=

37.6 g

Since this is the mass of

1

mole of gas, you can say that the molar mass of the gas is

molar mass = 37.6 g mol

−

1

−−−−−−−−−−−−−−−−−−−−−−−

Answer:

1.725e+18

Explanation:

Answer:

C. NH₄Cl

Explanation:

The compound with the element ratio 1 : 4 : 1 from the given choices is NH₄Cl.

An element is a pure substance made up of distinct number of atoms. Elements are unique and are different from other elements because of the nature of their atoms.

We often delineate an element using chemical symbols.

   In the compound NH₄Cl;

There are 3 elements:

           Number of atoms

N                      1

H                      4

Cl                     1

HCl as a limiting reactant

volume of the gas(H₂)= 0.672 L

mass of salt : =2.67 g

mass of excess left :  4.86 g

Given

5.4 g Al

300 mL of 0.2 mol/L HCl

Required

limitng reactants

volume of the gas(H₂)

mass of salt

mass of excess left

Solution

Reaction

2Al + 6HCl → 2AlCl₃ + 3H₂

mol Al = 5.4 g : 27 g/mol = 0.2

mol HCl = 0.3 L x 0.2 mol/L = 0.06

mol : coefficient of reactants :

Al = 0.2 : 2 = 0.1

HCl = 0.06 : 6 = 0.01

HCl as a limiting reactant(smaller ratio)

Al as an excess reactant

mol H₂ = 3/6 x mol HCl = 3/6 x 0.06 = 0.03

volume (STP : 1 mol=22.4 L) :

= 0.03 x 22.4 L

= 0.672 L

mol AlCl₃ = 2/6 x mol HCl = 2/6 x 0.06 = 0.02

mass AlCl₃ :

= mol x MW

= 0.02 x 133.5

=2.67 g

mol (reacted) : 2/6 x mol HCl = 2/6 x 0.06 = 0.02

mol (unreacted) : 0.2 - 0.02 = 0.18

mass = 0.18 x 27 g/mol = 4.86 g

Answer:

atoms

Explanation: