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2 years ago

Who proposed the "Law of Octaves" for organizing events?

Chemistry

1 answer:

djyliett [7]2 years ago

5 0

Explanation:

February 7, 1863, was the day John Newlands published a paper outlining what would be known as “The Law of Octaves”. Newlands discovered if he ordered the known elements by increasing atomic weight, the chemical properties of the elements would be similar for every eighth group

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Which of these compounds is a product of protein synthesis?

yuradex [85]

The answer is c it is Carbon Dioxide

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2 years ago

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Element A has a half-life of 10 days. A scientist measures out 200 g of this substance. After 30 days has passed, the scientist

myrzilka [38]

N=N₀*2^(-t/T)

N₀=200 g
T=10 d
t=30 d

N=200*2^(-30/10)=25 g

25 g will remain

4 0

2 years ago

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Ammonia reacts with sulfuric acid to produce the important fertilizer, ammonium hydrogen sulfate.

Liula [17]

Answer:

404.8g of (NH4)HSO4 is produced.

Explanation:

Step 1:

Data obtained from the question. This include the following:

Temperature (T) = 10°C = 10°C + 273 = 283K

Pressure (P) = 110KPa = 110/101.325 = 1.09atm

Volume (V) = 75L

Step 2:

Determination of the number of mole of ammonia, NH3.

The number of mole (n) of ammonia, NH3 can be obtained by using the ideal gas equation. This is illustrated below:

Note:

Gas constant (R) = 0.0821atm.L/Kmol

Number of mole (n) =?

PV = nRT

1.09 x 75 = n x 0.0821 x 283

Divide both side by 0.0821 x 283

n = (1.09 x 75) /(0.0821 x 283)

n = 3.52 moles

Step 3:

Determination of the number of mole ammonium hydrogen sulfate produced from the reaction.

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

NH3 + H2SO4 —> (NH4)HSO4

From the balanced equation above,

1 mole of NH3 produced 1 mole of (NH4)HSO4

Therefore, 3.52 moles of NH3 will also produce 3.52 moles of (NH4)HSO4.

Therefore, 3.52 moles of ammonium hydrogen sulfate, (NH4)HSO4 is produced.

Step 4:

Conversion of 3.52 moles of ammonium hydrogen sulfate, (NH4)HSO4 to grams. This is illustrated below:

Molar Mass of (NH4)HSO4 = 14 + (4x1) + 1 + 32 + (16x4) = 115g/mol

Number of mole of (NH4)HSO4 = 3.52 moles

Mass of (NH4)HSO4 =..?

Mass = mole x molar Mass

Mass of (NH4)HSO4 = 3.52 x 115 = 404.8g

Therefore, 404.8g of (NH4)HSO4 is produced.

5 0

2 years ago

How many moles of mercury(II) oxide, HgO, are needed to produce 125 g of oxygen, O2? How many moles of mercury is produced?

iren2701 [21]

Answer: 7.81 mol HgO (How many moles of mercury(II) oxide, HgO, are needed to produce 125 g of oxygen, O2?)

Explanation:

7 0

2 years ago

Write the complete symbol, including mass number and atomic number, for each atom.

Reil [10]

Answer:

a) 58Ni

b) 43Ti

c) 34P

d) 18O

e) 58Ni

f) 43Ti

g)34P

h) 18O

i) 54Cr

Explanation:

a) contains 28 protons and 30 neutrons:

An atom with 28 protons and 30 neutrons has an atomic number of 28 and a mass number of (30+28) = 58.

The atom with atomic number 28 is Ni.

b) contains 22 protons and 21 neutrons:

An atom containing 22 protons and 21 neutrons has an atomic number of 22 and an atomic mass of (22+21) = 43

The atom with atomic number 22 is Titanium (Ti).

This is the 43Ti isotope of titanium

c) contains 15 electrons and 19 neutrons

An atom with 15 electrons would have the same amount of , 15 protons (considering it to be neutral) and has 19 neutrons.

Thus, the atomic number of the atom would be 15 and the mass number would be (15+19) = 34

The atom with atomic number 15 is phosphorus (P).

This is the 34P isotope of phosphorus

d) an oxygen atom with 10 neutrons:

Oxygen has an atomic number of 8, thus there are 8 protons in an atom of oxygen.

The mass number of the oxygen atom with 10 neutrons would be (8+10) = 18

This is 18O - isotope.

e) contains 28 protons and 30 neutrons:

An atom with 28 protons and 30 neutrons has an atomic number of 28 and a mass number of (30+28) = 58.

The atom with atomic number 28 is Ni.

f) contains 22 protons and 21 neutrons:

An atom containing 22 protons and 21 neutrons has an atomic number of 22 and an atomic mass of (22+21) = 43

The atom with atomic number 22 is Titanium (Ti).

This is the 43Ti isotope of titanium

g) contains 15 electrons and 19 neutrons:

An atom with 15 electrons would have the same amount of , 15 protons (considering it to be neutral) and has 19 neutrons.

Thus, the atomic number of the atom would be 15 and the mass number would be (15+19) = 34

The atom with atomic number 15 is phosphorus (P).

This is the 34P isotope of phosphorus

h) an oxygen atom with 10 neutrons:

Oxygen has an atomic number of 8, thus there are 8 protons in an atom of oxygen.

The mass number of the oxygen atom with 10 neutrons would be (8+10) = 18

This is 18O - isotope.

i) The atomic number of Cr is 24

The mass number is given to be 54.

This is the 54Cr isotope and has 24 protons and 30 neutrons

8 0

3 years ago