A solution of naoh has a concentration of 25% by mass. what mass of naoh is present in 0.250 g of this solution? use the periodic table in the toolbar if needed. g

Answer:

answer is A. Hypothesis on edge 2020

Explanation:

have a great day peeps :)

a)32.670 + 1.2240 = 33.8904

33.8904-14.0 = 19.8904

b)12.080 × 4.050 × 0.231

=54.36 × 0.231

=12.55716

c)(3.051 × 103) ×(2.00 × 10.2)=

314.253 × 20.4 = 6410.7612

Answer:andre plates is thin

Explanation:

Explanation:

one mole of any substance there are 6.022×1023 units of that substance. (This number is called Avogadro's number, NA.)

We need to convert the mass of silicon to moles using the molar mass of silicon, 28.06gmol. This number means that one mole of pure silicon would have a mass of 28.06g. Our given mass, however, is in milligrams; to convert this to grams we'll use the conversion factor 1g103mg:

5.86mg Si(1g103mg)=0.00586g Si

Now, using silicon's molar mass, we'll convert this mass to moles of Si:

0.00586g Si(1mol Si28.06g Si)=2.09×10−4mol Si

Finally, let's use Avogadro's number to convert

The number of atoms in a 92.8 mg sample of Si is 1.99×10²¹ atoms

From Avogadro's hypothesis, we understood that:

Recall,

1 mole of Si = 28.09 g

Now, we shall convert 28.09 g to mg. This can be obtained as follow:

1 g = 1000 mg

Therefore,

28.09 g = 28.09 × 1000

Thus, 28.09 g is equivalent to 28090 mg

Therefore,

Finally, we shall determine the number of atoms in 92.8 mg sample of Si. This can be obtained as follow:

28090 mg of Si = 6.02×10²³ atoms

Therefore,

92.8 mg of Si = [tex]\frac{92.8 * 6.02*10^{23}}{28090}\\[/tex]

Thus, 92.8 mg sample of Si contains 1.99×10²¹ atoms

Learn more: https://brainly.com/question/5809151

Answer:

v = 658.82 km/h

Explanation:

The distance between New York and London is [tex]5.6\times 10^3\ km[/tex]

Time taken from New York to London is 8.5 hours

We need to find the average speed of the plane.

Total distance covered divided by the total time taken is equal to the average speed of an object. So,

[tex]v=\dfrac{d}{t}\\\\v=\dfrac{5.6\times 10^3\ km}{8.5\ h}\\\\v=658.82\ km/h[/tex]

So, the average speed of the plane is 658.82 km/h.

Answer:

2H3PO4+ 3Ca(OH)2=Ca3(PO4)2+6H20

Answer:

Possibly

Explanation:

Answer:

hello your question is incomplete the options are missing

Determine the resultant velocity for the plane when it is travelling

i) To the east

ii) To the west

answer :i)  270 i

             ii)  -150 i

Explanation:

velocity of Airplane = 210 m/s

wind velocity = 60 m/s to the east

The resultant velocity for the plane when it is travelling  

let the velocity of the wind = V2

           velocity of the plane = v1

i) The resultant velocity for the plane when travelling to the east

Vr = V2 i  + V1 i

Vr= 60i + 210i  = 270i

ii) resultant velocity when the plane is travelling to the west

Vr = - V1 i + V2i

     = -210i  + 60 i = -150 i  

Answer:

I believe the boiling point is 102 degrees Celsius and the freezing point is -2 degrees Celsius (so C).

Explanation:

Gas has a higher entropy than liquid, who has a higher entropy than solid. If a solid melts or a liquid vaporizes, the entropy increases. If a solute is present, it also contributes to the entropy of the mixture. The liquid already has a higher entropy (molecule randomness or disorder) than the pure liquid, so there's less likelihood of forming gas. This, therefore, means that it has a higher boiling point. This randomness also opposes freezing. A lower temperature has to reached before balance between solid and solution reached. So, the freezing point is lower.

Please let me know if I'm incorrect :)

Answer:

1. Mixtures

2. Solutions

3. Heterogeneous

4. Sand-water

5. Salt-water mixture

6. Water

Explanation:

1. Indeed, Matter could exist and substances or Mixtures, which is also subdivided into two.

2. These substances can also be in the form of solutions.

3. Heterogeneous on the other hand refers to mixtures that are not totally uniform such as Sand-water.

4. Sand-water are good examples of Heterogeneous mixtures.

5. Salt-water mixture falls under the category of homogeneous mixtures as they are totally uniform.

6. Water is also an example of a homogeneous mixture because basically two elements Hydrogen and Oxygen combine uniformly to form water.

Answer:

vines or body vessels

Explanation:

Veins are vessels of the circulatory system that support circulation by conveying blood to the heart. Blood flowing through the circulatory system transports nutrients, oxygen, and water to cells throughout the body.

Answer: Respiratory system.

Explanation: The cardiovascular system transports oxygen and carbon dioxide for the respiratory system. Not the best explanation but I hope this help ya, good luck! ;D

1. V= 161

2. V = 37.3

Charles's Law states that  

When the gas pressure is kept constant, the gas volume is proportional to the temperature  

[tex]\tt \dfrac{V1}{T1}=\dfrac{V2}{T2}[/tex]

1.

[tex]\tt \dfrac{125}{17+273.15~K}=\dfrac{V2}{100+273.15}\\\\V2=160.7\rightarrow 161~cm^3[/tex]

2.

[tex]\tt \dfrac{27.3}{0+273.15`K}=\dfrac{V2}{100+273.15}\\\\V2=37.3~cm^3[/tex]

earths gravitational field?

Answer:

ummmmmmmmmmmmmmmm

Explanation:

Answer: well im taking the test right now. and i dont know so yah. good luck HAH

Explanation:

Answer:

the correct answer is B. far left

Explanation:

i just got it right on edge 2020 :p

Answer:

CH4

Explanation:

The intensive properties among the options provided are:

A) a substance has a density of 4.13 g/cm3

D) a substance has a mass of 1.25 g

E) a substance has a volume of 5.4 mL

Intensive properties are those that do not depend on the amount or size of the substance but are characteristic of the substance itself.

These properties, density, mass, and volume, are intrinsic to the substance and do not change with the quantity of the substance present. They are independent of the amount of the substance and remain constant regardless of the sample size.

On the other hand, melting point (B) and malleability (C) are not considered intensive properties. Melting point can vary depending on external conditions such as pressure, and malleability is influenced by the structure and composition of the substance, which can be affected by impurities or processing methods. These properties can change with the amount or size of the substance and are considered extensive properties.

Learn more about Intensive properties from the link given below.

https://brainly.com/question/13055036

#SPJ2

Answer:

7/9

Explanation:

4+3=7

leave the denominators be

The moles of iron(III) oxide are :

- 4 moles

Given:

           moles of Fe (iron) = ?

           moles of Oxygen (O₂) = 3.0 moles

Reaction :

            4Fe + 3O₂ -------->  2Fe₂O₃

           4Fe  + 3O₂ ----------> 2Fe₂O₃

           4 mole +3 mole

Unity formula:

                    4 mole of iron (Fe) ≅ 3 moles of oxygen (O₂)

                    ??mole of iron (Fe) ≅ 3.0  moles of oxygen (O₂)

Cross multiplication:

                 moles of iron (Fe) =  3.0 moles *4 mole/ 3 moles

                 moles of iron (Fe) = 4 moles

moles of iron(III) is 4 moles produced from 3.0 moles of oxygen.

Learn more about "Mole Concept":

https://brainly.com/question/10488966?referrer=searchResults

Answer: ITS D

Explanation: i was just looking answers for my test and this is my sisters account

Answer:

Amount left after 140 days is 38.125 g.

Explanation:

Given data:

Half life of Co-59 = 35 days

Total mass of sample = 610.0 g

Sample remain after 140 days = ?

Solution:

Number of half lives passes during 140 days:

Number of half lives  = T elapsed / Half lives

Number of half lives  = 140 days / 35 days

Number of half lives  = 4

Amount left:

At time zero = 610 g

At first half life = 610 g/2 = 305 g

At second half life = 305 g/2 = 152.5 g

At 3rd half life = 152.5 g/2 = 76.25 g

At 4th half life = 76.25 g /2 =38.125 g

Amount left after 140 days is 38.125 g.

Answer:

2P + 3Cl2 => 2PCl3

Explanation:

Answer:

pp

Explanation:

Answer:

The correct name is barium (dihydrogen/dihydride

Explanation:

Google

Answer:

c

Explanation:

i read a artical on him and it said

love yall;]

Answer: It is a Heterogeneous mixture.