Why do scientists need a universal system to classify organisms?

Answer:

Mass = 3.24 g

Explanation:

Given data:

Number of atoms of cobalt = 3.31 × 10²² atoms

Mass of cobalt = ?

Solution:

We will calculate the number of moles of cobalt first.

1 mole contain 6.022× 10²³ atoms

3.31 × 10²² atoms  × 1 mol / 6.022× 10²³ atoms

0.0549 mol

Mass of cobalt:

Mass = number of moles × molar mass

Mass = 0.0549 mol × 58.93 g/mol

Mass = 3.24 g

Answer: 3.61 L

Explanation:

To calculate the moles, we use the equation:

[tex]moles=\frac{\text {given mass}}{\text {Molar mass}}[/tex]

[tex]moles=\frac{12.26g}{122.6g/mol}=0.1moles[/tex]

[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]

2 moles of  [tex]KClO_3[/tex]  produce = 3 moles of  [tex]O_2[/tex]

0.1 moles of  [tex]KClO_3[/tex] produce = [tex]\frac{3}{2}\times 0.1=0.15[/tex] moles of    [tex]O_2[/tex]

According to the ideal gas equation:'

[tex]PV=nRT[/tex]

P = Pressure of the gas = 1 atm (NTP)

V= Volume of the gas = ?

T= Temperature of the gas = 20°C = (20+273) K = 293 K    (NTP)

R=  Value of gas constant in in kilopascals = 0.0821 Latm/K mol

[tex]1\times V=0.15\times 0.0821\times 293[/tex]

[tex]V=3.61L[/tex]

Thus volume of oxygen at NTP obtained by decomposing 12.26 g of  [tex]KClO_3[/tex] is 3.61 L

love duuuh dumm dumm

2MnO4-(aq) + 16H+ + 10Cl-(aq) ⇔ 2Mn2+(aq) + 8H2O + 5Cl2 (g)

Given

Reaction(unbalanced)

Mno4- (aq) + Cl- (aq) → Mn2+ + Cl2 (g)

Required

Half reaction

Solution

1. Add coefficient(equalizing atoms in reaction)

2. Adding H₂O on the O-deficient side.  

3. Adding H⁺ on the H-deficient side.  

4. Adding e⁻

5. Equalizing the number of electrons and sum the all the half-reaction

1.MnO₄⁻(aq) = Mn²⁺(aq) reduction

2.MnO4(aq) = Mn2+(aq) + 4H2O

3. MnO4-(aq) + 8H+ = Mn2+(aq) + 4H2O

4. MnO4-(aq) + 8H+ + 5e- = Mn2+(aq) + 4H2O

Cl⁻(aq) = Cl₂(g) oxidation

1. 2Cl-(aq) = Cl2 (g)

2-3 none

4. 2Cl-(aq) = Cl2 (g) + 2e-

5.

MnO4-(aq) + 8H+ + 5e- = Mn2+(aq) + 4H2O x2

2Cl-(aq) = Cl2 (g) + 2e-                                    x5

2MnO4-(aq) + 16H+ + 10e- = 2Mn2+(aq) + 8H2O

10Cl-(aq) = 5Cl2 (g) + 10e-    

2MnO4-(aq) + 16H+ + 10Cl-(aq) ⇔ 2Mn2+(aq) + 8H2O + 5Cl2 (g)

Answer:

phosphorus.

Explanation:

The atomic number of phosphorus is 15 so the protons will be 15.

Answer:

The name is phosphorus and the number of atomic is 15

Explanation:

Answer:

1. 1.93 mole N2

2. 3.5 mole MgO

3. 3.20 mole FeCI3

Answer:

1) 3 2) 2 3) 1 4) 3

Explanation:

so on the reactant side (left), there is 2 H, 1 CO3, and 1 Fe. On the product side (right) there is 2 Fe, 3 CO3, and 2 H2. So to start I added a 3 in the first blank to make CO3 equal on both sides. In doing this, there is not 2 H, there is now 6 so I added a 3 in the 4th blank. Currently, H and CO3 are equal on both sides but not Fe. So I added a 2 in the 2nd blank. I didn't add anything in the 3rd blank so it is an understood 1.

The balanced equation

3H₂CO₃ + 2Fe → Fe₂(CO₃)₃ + 3H₂

Given

Reaction

H₂CO₃ + Fe → Fe₂(CO₃)₃ + H₂

Required

Coefficient of the reaction

Solution

aH₂CO₃ + bFe → Fe₂(CO₃)₃ + cH₂

Prioritize balancing the elements that form the most complex compounds

Fe, left = b, right = 2⇒b=2

C, left = a, right = 3⇒a=3

H, left = 2a, right = 2c⇒2a=2c⇒2.3=2c⇒6=2c⇒c=3

The equation becomes :

3H₂CO₃ + 2Fe → Fe₂(CO₃)₃ + 3H₂

Answer:

M₂ = 0.34 M

Explanation:

Given data:

Molarity of NaOH =M₁ =  0.200 M

Volume of HF =V₂=  18.25 mL

Volume of NaOH added = V₁ = 31.20 mL

Molarity of HF solution = M₂ = ?

Solution:

M₁V₁  =  M₂V₂

by putting values,

0.200 M × 31.20 mL = M₂ × 18.25 mL

M₂ = 0.200 M × 31.20 mL /  18.25 mL

M₂ = 6.24 M.mL / 18.25 mL

M₂ = 0.34 M

Answer:

Mercury is released into the environment from many sources. Mercury becomes airborne when rocks erode, volcanoes erupt and soil decomposes. It then circulates in the atmosphere and is redistributed throughout the environment.

I think this is right.

Answer:

A. Each amino acid has an amino group and a carboxyl group.

Answer:a

Explanation:

Moles of hydronium (H₃O⁺) : 2.5 x 10⁻⁴

Given

pH = 4.3

V sample = 5 L

Required

moles of H₃O⁺(hydronium)

Solution

pH = - log [H₃O⁺]

4.3 = - log [H₃O⁺]

[tex]\tt [H_3O^+]=10^{-4.3}~M=10^{-4.3}mol/L[/tex]

Moles of hydronium for 5 L sample :

[tex]\tt 5~L\times 10^{-4.3}mol/L=5.10^{-4.3}moles=2.5\times 10^{-4}~moles[/tex]

Answer:

B

Explanation:

add a subscript of 4 after the O

I just took this quiz

The next step Sebastian will take after identifying the chemical symbols is add a subscript of 4 after the O.

The chemical formula of a compound shows the arrangement of the constituent atoms in that compound.

According to this question, Sebastian wants to write the chemical formula for phosphorus tetraoxide. He initially identifies the chemical symbols as P and O.

The next step for Sebastian to take is add a subscript of 4 after the O to make the PO4 chemical formula.

Learn more about chemical formula at: https://brainly.com/question/11140581

Answer:

1.0 is Answer

Explanation:

May be this is helpful!

Answer:

From 13 moles of CuO 4.3 moles of N₂ are formed

Explanation:

Given data:

Number of moles of N₂ formed = ?

Number of moles of CuO react = 13 mol

Solution:

Chemical equation:

2NH₃ + 3CuO     →    3Cu + N₂ + 3H₂O

Now we will compare the moles of CuO and N₂.

                CuO         :              N₂

                   3            :              1

                   13          :           1/3×13 = 4.3 mol

Thus, from 13 moles of CuO 4.3 moles of N₂ are formed.

From 13 moles of CuO 4.3 moles of N₂ are formed.

Given:

Number of moles of CuO react = 13 mol

To find:

Number of moles of N₂ formed = ?

The balanced chemical equation:

2NH₃ + 3CuO → 3Cu + N₂ + 3H₂O

On comparing the moles of CuO and N₂.

CuO : N₂

3 : 1

13 : 1/3*13 = 4.3 mol

Thus, from 13 moles of CuO 4.3 moles of N₂ are formed.

Learn more:

brainly.com/question/13314627

Answer:

See explanation

Explanation:

A word equation tries to depict a chemical reaction in words. Letters rather than only chemical formulas are used to show the reaction equation.

Now we want to write a word equation that shows the reaction of sodium hydroxide solution and aluminium sulphate solution:

Alumunium sulphate + sodium hydroxide ------>Aluminium hydroxide + sodium sulphate

Answer:

Its oxygen

Explanation:

Look at the 2nd row in the periodic table and the 6th element in the row.

Lithium has 1 valence electron in the 2nd energy level

Beryllium has  2 valence electron in the 2nd energy level

Eventually, u will reach Oxygen with 6

The one above is wrong

Answer:

CH (92.2% C; 7.8% H), or just CH2

Answer:

Fluorine.

Explanation:

Fluorine has more protons resulting in a greater nuclear charge, causing a greater attraction for electrons. ... Fluorine has a smaller radius than lithium because of the greater positive charge of the nucleus, pulling electrons and the electron shells in closer.

Answer:

14g

Explanation:

The empirical formula of the compound is CH₂ ;

When we are dealing with compounds the gram formula mass or gram - molecular weight is the molar mass of the compound.

It is determined by adding the atomic masses of the components together and then expressed in grams.

 Atomic mass of C  = 12

 Atomic mass of H  = 1

  Gram formula mass = 12 + 2(1)  = 14g

The alkali metals (1A) show the least electronegativity among the groups of elements listed.

Electronegativity is the tendency of an atom to attract electrons towards itself when it forms a chemical bond with another atom. It is determined by factors such as the nuclear charge, atomic radius, and electron configuration of the atom.

Elements with high electronegativity values, such as the halogens (7A) and oxygen, tend to attract electrons strongly and form negative ions or polar covalent bonds.

On the other hand, elements with low electronegativity values, such as the alkali metals (1A) and alkaline earth metals (2A), have weak tendencies to attract electrons and are more likely to lose electrons and form positive ions in chemical reactions.

Among the groups listed, the alkali metals have the lowest electronegativity values, as they have a single valence electron that is located far from the nucleus and shielded by inner electrons. This makes them highly reactive and easily form cations in ionic compounds.

Find more on electronegativity:

https://brainly.com/question/17762711

#SPJ7

Answer:

In atomic physics, the Bohr model or Rutherford–Bohr model, presented by Niels Bohr and Ernest Rutherford in 1913, is a system consisting of a small, dense nucleus surrounded by orbiting electrons—similar to the structure of the Solar System, but with attraction provided by electrostatic forces in place of gravity.

Explanation:

Answer:

In atomic physics, the Bohr model or Rutherford–Bohr model, presented by Niels Bohr and Ernest Rutherford in 1913, is a system consisting of a small, dense nucleus surrounded by orbiting electrons—similar to the structure of the Solar System, but with attraction provided by electrostatic forces in place of gravity

Answer:

D.H2CO3

Explanation:

answer is d h2co3

Mark as brainliest my G

I am unsure if this is correct, but this might be the whole section:

Answer and Explanation:

Your mass is the same no matter where you go in the universe; your weight, on the other hand, changes from place to place. Mass is measured in kilograms; even though we usually talk about weight in kilograms, strictly speaking, it should be measured in newtons, the units of force. (according to cosmicmagazine.com)(not my writing or explanation)

Answer:

hey there!

I hope this is correct it is a adult plant

Answer:

Magnesium

0.003mole

Explanation:

The problem here entails we find the metal in the carbonate.

 For group 2 member, let the metal  = X;

 The carbonate is XCO₃;

 If we sum the atomic mass of the elements in the metal carbonate, we should arrive at 84g/mol

 Atomic mass of C = 12g/mol

                            O  = 16g/mol

 Atomic mass of X + 12 + 3(16)  = 84

  Atomic mass of X  = 84 - 60  = 24g/mol

The element with atomic mass of 24g is Magnesium

B.

Number of moles in 0.3g of CaCO₃:

     Molar mass of CaCO₃   = 40 + 12 + 3(16)  = 100g/mol

 Number of moles = [tex]\frac{mass}{molar mass}[/tex]  

 Number of moles  = [tex]\frac{0.3}{100}[/tex]   = 0.003mole