hello, can someone help? i’ve been stuck on this for a few days... it will be greatly appreciated if u help T-T thanks in advance

Answer:

Plssssssssd can you translate to English???

Answer:

D ) Chemical Change

Explanation:

What were Lamarck's ideas about evolution and Why were those ideas incorrect?

→ These and other examples show that Lamarck's theory does not explain how life formed and became the way it is. The other way that Lamarck's theory has been proven wrong is the study of genetics. Darwin knew that traits are passed on, but he never understood how they are passed on.

Answer:

There are [tex]6.01\times 10^{23}[/tex] number of molecules.

Explanation:

Given that,

Volume, V = 22.4 L

Temperature, T = 0°C = 273.15 K

Pressure, P = 1 atm = 1.013 bar

We need to find the number of molecules. Let there are n number of molecules. We know that, ideal gas law is as follows :

[tex]PV=nRT\\\\n=\dfrac{PV}{RT}\\\\n=\dfrac{1.013\times 22.4}{0.08 314\times 273.15}[/tex]

n = 0.999 moles

No. of molecules,

[tex]N=n\times N_A\\\\=0.999\times 6.023\times 10^{23}\\\\N=6.01\times 10^{23}[/tex]

So, there are [tex]6.01\times 10^{23}[/tex] number of molecules.

Answer:

im really sorry but i dont no☹

Explanation:

Normally, fusion involves two heavy hydrogen nuclides but since we have 4 light hydrogen nuclides, two of which underwent positron emission, thus changing two protons into neutrons plus 2 positrons and 2 neutrinos. The resulting nucleus from this fusion reaction is an He-4 nucleus.

V2 = 276 ml

Explanation:

Given:

V1 = 250 ml V2 = ?

T1 = 293K. T2 = 324K

Here, we use Charles's law:

V1/T1 = V2/T2

Solving for P2, we get

V2 = (T2/T1)V1

= (324K/293K)(250 ml)

= 276 ml

Answer:

Explanation:

Step 1: Calculate the amount of sodium hydroxide in moles

Volume of sodium hydroxide solution = 25.0 ÷ 1,000 = 0.0250 dm3

Rearrange:

Concentration in mol/dm3 =

Amount of solutein mol = concentration in mol/dm3 × volume in dm3

Amount of sodium hydroxide = 0.100 × 0.0250

= 0.00250 mol

Step 2: Find the amount of hydrochloric acid in moles

The balanced equation is: NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

So the mole ratio NaOH:HCl is 1:1

Therefore 0.00250 mol of NaOH reacts with 0.00250 mol of HCl

Step 3: Calculate the concentration of hydrochloric acid in mol/dm3

Volume of hydrochloric acid = 20.00 ÷ 1000 = 0.0200 dm3

Concentration in mol/dm3 =

Concentration in mol/dm3 =

= 0.125 mol/dm3

Step 4: Calculate the concentration of hydrochloric acid in g/dm3

Relative formula mass of HCl = 1 + 35.5 = 36.5

Mass = relative formula mass × amount

Mass of HCl = 36.5 × 0.125

= 4.56 g

So concentration = 4.56 g/dm3

Answer:

BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

The activity of four unknown metals based on their chemical changes is option B.

Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.

There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.

There are three types of chemical changes:

1) inorganic changes

2)organic changes

3) biochemical changes

During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.

Learn more about chemical change,here:

https://brainly.com/question/23693316

#SPJ3

Answer:

what's the question?? I see nothing

Answer:

However

Explanation:

sounds the best and makes since

Answer:

A. 2AgI + Na2S → Ag2S + 2NaI

B. Na3PO4 + 3HCl → 3NaCl + H3PO4

C. Ba3N2 + 6H2O → 3Ba(OH)2 + 2NH3

D. TiCl4 + 2H2O → TiO2 + 4HCl

E. 3CaCl2 + 2Na3PO4 → Ca3(PO4)2 + 6NaCl

Explanation:

Answer:

d.) 1.0 M HNO2, 1.0 M NaNO2

Explanation:

A buffer is a mixture that is capable of tolerating addition of a strong acid or base without altering the pH substantially.

A buffer is the mixture of a WEAK ACID AND ITS CONJUGATE BASE or a WEAK BASE AND ITS CONJUGATE ACID

In the problems:

a) HCl is a strong acid and NaCl a salt. NO buffer

b) NH3 is a weak base and NaCL a salt. NO buffer

c) HF is a weak acid and NaCl a salt. NO buffer.

Solution :

[tex]$H_2 +I_2\rightleftharpoons 2HI$[/tex]

Initial concentration               Equilibrium concentration           [tex]$K_c=\frac{[HI]^2}{[H_2][I_2]}$[/tex]

  (mol/L)                                           (mol/L)

[tex]$[H_2]$[/tex]                 [tex]$[I_2]$[/tex]            [tex]$[HI]$[/tex]    [tex]$[H_2]$[/tex]                 [tex]$[I_2]$[/tex]            [tex]$[HI]$[/tex]

[tex]$2.4 \times 10^{-2}$[/tex]     [tex]$1.38 \times 10^{-2}$[/tex]  0     [tex]$1.14 \times10^{-2}$[/tex]    [tex]$0.12 \times 10^{-2}$[/tex]  [tex]$2.52 \times 10^{-2}$[/tex]        46.42

[tex]$2.4 \times 10^{-2}$[/tex]     [tex]$1.68 \times 10^{-2}$[/tex]  0     [tex]$0.92 \times10^{-2}$[/tex]    [tex]$0.20 \times 10^{-2}$[/tex]  [tex]$2.96 \times 10^{-2}$[/tex]        47.61

[tex]$2.4 \times 10^{-2}$[/tex]     [tex]$1.98 \times 10^{-2}$[/tex]  0     [tex]$0.77 \times10^{-2}$[/tex]    [tex]$0.31 \times 10^{-2}$[/tex]  [tex]$3.34 \times 10^{-2}$[/tex]        46.73

[tex]$2.4 \times 10^{-2}$[/tex]     [tex]$1.76 \times 10^{-2}$[/tex]  0     [tex]$0.92 \times10^{-2}$[/tex]    [tex]$0.22 \times 10^{-2}$[/tex]  [tex]$3.08 \times 10^{-2}$[/tex]        46.86

[tex]$0$[/tex]                  [tex]$0$[/tex]        [tex]$3.04 \times 10^{-2}$[/tex]     [tex]$0.345 \times10^{-2}$[/tex]    [tex]$0.345 \times 10^{-2}$[/tex]  [tex]$2.35 \times 10^{-2}$[/tex] 46.39

[tex]$0$[/tex]                  [tex]$0$[/tex]        [tex]$7.58 \times 10^{-2}$[/tex]     [tex]$0.86 \times10^{-2}$[/tex]    [tex]$0.86 \times 10^{-2}$[/tex]  [tex]$5.86 \times 10^{-2}$[/tex]     46.42

Average [tex]$K_c=46.738$[/tex]

Answer:

(I) [tex] m_{ZnCl_{2}} = 34.07 g [/tex]  

(II) [tex] \% y = 176.4 \% [/tex]

(III) The presence of impurities in the 32.70 g of zinc will support the student's percentage yield.

Explanation:

The reaction is:

Zn + 2HCl → ZnCl₂ + H₂

(I) To find the number of moles of ZnCl₂ we need to calculate the number of moles of the reactants.

[tex] n_{Zn} = \frac{m}{A} [/tex]

Where:

m: is the mass

A: is the standard atomic weight  

[tex] n_{Zn} = \frac{32.70 g}{65.38 g/mol} = 0.50 moles [/tex]

[tex] n_{HCl} = \frac{18.23 g}{36.458 g/mol} = 0.50 moles [/tex]

If 1 mol of Zn reacts with 2 moles of HCl, the number of moles of Zn needed to react with 0.50 moles of HCl is:              

[tex] n_{Zn} = \frac{1 mol Zn}{2 moles HCl}*0.50 moles HCl = 0.25 moles [/tex]  

Then, the limiting reactant is HCl. Now, we can find the number of moles of ZnCl₂ by knowing that 2 moles of HCl produce 1 mol of ZnCl₂.

[tex] n_{ZnCl_{2}} = \frac{1 mol ZnCl_{2}}{2 moles HCl}*0.50 moles = 0.25 moles [/tex]    

Finally, the mass of ZnCl₂ that he has produced is:            

[tex] m_{ZnCl_{2}} = n_{ZnCl_{2}}*M = 0.25 moles*136.286 g/mol = 34.07 g [/tex]  

(II) The percentage yield can be found with the following equation:

[tex] \% y = \frac{m_{e}}{m_{t}} \times 100 [/tex]

Where:      

[tex] m_{e}[/tex]: is the experimental mass = 60.1 g

[tex] m_{t}[/tex]: is the theoretical mass = 34.07 g

Hence, the percentage yield is:  

[tex] \% y = \frac{60.1 g}{34.07 g} \times 100 = 176.4 \% [/tex]

(III) The presence of impurities in zinc will explain why the percentage yield is greater than 100% because the mass of the impurities will make the mass of zinc bigger than its mass without impurities. If there were no impurities in the zinc, its mass would be smaller and thus the percent yield.

I hope it helps you!                  

Answer:

Electrons and protons are not positively charged

Explanation:

Neutrons are the only ones positively charged in the structure of an atom.... Also like charges repel which means a -ive and a - ive will repel when together

Answer:

1045 J

Explanation:

By using the formula Eh= mass×specific heat capacity × change in tempreture

With it being a known fact that the specific heat capacity of water is 4.16g/j/°c

Answer:

A base is weak when only a little of it is dissolved in water

Explanation:

Answer: B.) A base is weak when only a little of it is dissolved in water

Hope this helps :)

Answer:

The respiratory system is the network of organs and tissues that help you breathe. basically your airways, lungs, and blood vessels so you quite literally need these to survive I mean your muscles need oxygen to function and your brain needs oxygen to function so without your respiratory system you wouldn't be able to move much and you would quickly pass out and die from the lack of oxygen to your brain there are other body processes that need oxygen as well but these are just two examples.

Explanation:

Answer:

Maybe it’s dark ??????????????

Explanation:

Hm

Answer:

a) anode - hydrogen gas

cathode - oxygen gas

b) hydrogen gas - The gas burns with a pop sound

Oxygen gas - The gas rekindles a glowing splint

c) The volume of gas produced at the anode is 60cm3

Explanation:

The electrolysis of water produces two volumes of hydrogen at the anode and one volume of oxygen at the cathode.

The hydrogen gas burns with a pop sound. It is easily identified by this test. Also, oxygen is known to rekindle a glowing splint and this is a commonly used test for oxygen gas.

Since the ratio of hydrogen produced at the anode to oxygen produced at the cathode is 2:1 by volume; then when 30cm3 of oxygen is produced at the cathode, 60cm3 of hydrogen is produced at the anode.

Answer:

one to one

Explanation:

Answer:

In the ionic solid sodium chloride, there is one to one ratio of sodium ions to chloride ions

Answer:

[tex]pH=14.2[/tex]

Explanation:

Hello there!

In this case, according to the information in this problem, and considering these two bases are strong, it is necessary for us to calculate the total moles of OH ions as shown below:

[tex]n_{OH^-}^{from\ NaOH}=0.050L*1.0mol/L=0.050mol\\\\n_{OH^-}^{from\ Ba(OH)_2}=0.050L*1.0mol/L*2=0.10mol\\\\n_{OH^-}^{tot}=0.15mol[/tex]

Now, the as the solutions are additive, the total volume is then 0.100 L and the concentration:

[tex][OH^-]=\frac{0.15mol}{0.100L}=1.5[/tex]

And therefore, the pH is:

[tex]pH=14+log(1.5)\\\\pH=14.2[/tex]

Regards!

Answer: The molar mass of the gas is 9.878 g/mol.

Explanation:

According to Graham's law, the rate of diffusion is inversely proportional to square root of molar mass of gas.

[tex]Rate = \frac{1}{\sqrt{M}}[/tex]

where,

M = molar mass of gas

As given gas diffuses 1/7 times faster than hydrogen gas. So, its molar mass is calculated as follows.

[tex]\frac{R_{1}}{R_{2}} = \sqrt{\frac{M_{2}}{M_{1}}}\\[/tex]

where,

[tex]M_{1}[/tex] = molar mass of hydrogen gas

[tex]M_{2}[/tex] = molar mass of another given gas

[tex]R_{1}[/tex] = rate of diffusion of hydrogen

[tex]R_{2}[/tex] = rate of diffusion of another given gas = [tex]\frac{1}{7}R_{1}[/tex]

Substitute the values into above formula as follows.

[tex]\frac{R_{1}}{R_{2}} = \sqrt{\frac{M_{2}}{M_{1}}}\\\frac{R_{1}}{\frac{1}{7}R_{1}} = \sqrt{\frac{M_{2}}{2}}\\7 \times 1.414 = M_{2}\\M_{2} = 9.878 g/mol[/tex]

Thus, we can conclude that the molar mass of the gas is 9.878 g/mol.

Answer:

98.78 g/mol

Explanation:

Just took the test

Answer:

One.

Explanation:

this is the structure of lithium which has valency 1 .Valency means no.electrons present in outermost shell or needed electrons to complete octet

Answer:D

Explanation:

Answer: The Diamond hotel, because the ocean will carry warm air towards the inland regions.

Explanation: If Diamond hotel is inland then it will be the warmest, Its colder by the ocean and sometime summer isnt even warm by the ocean. The answer is D, or number 4

Hope this helps

Answer:

Failure to conserve water during irrigation can lead to an increase in pollution that results from runoff. Natural filters are diminished by the overuse of water resources, which leads to an increase in water contamination that would have been filtered by these natural sources.

Explanation:

Answer:

a. Overirrigating fields causes an increase in pollution that results from runoff.

b. Natural water filters are depleted by the overuse of water.

c. Sewage systems are more likely to fail due to greater demand, causing higher chances of water contamination.

Answer:

false

Explanation:

you have bromine , its a non metal and liquid in room temperature

Answer:

"0.24 J/g.k" is the appropriate solution.

Explanation:

Mass of substance,

m = 110.00 g

Heat,

q = 396 J

Change in temperature,

ΔT = 15.0°C  

Now,

The specific heat will be:

⇒  [tex]q=ms \Delta T[/tex]

On putting the given values, we get

⇒  [tex]396=110.00\times s\times 15.0[/tex]

⇒  [tex]396=s\times 1650[/tex]

⇒      [tex]s=\frac{396}{1650}[/tex]

⇒         [tex]=0.24 \ J/g.k[/tex]