Polyatomic ions

Define: Atomic Mass, Mass Number, Isotope

Westkost [7]

Answer:

Explanation:

the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.

the total number of protons and neutrons in a nucleus.

to write the symbol for an isotope, place the atomic number as a subscript and the mass number (protons plus neutrons) as a superscript to the left of the atomic symbol

5 0

3 years ago

Who is the father of tillage?

Katen [24]

Answer: Jethro Tull is the father of tillage and he wrote a book horse hoeing husbandry and coined the term weed and zero tillage.

Explanation:

6 0

3 years ago

For the net reaction: 2AB + 2C → A2 + 2BC, the following slow first steps have been proposed. AB → A + B 2C + AB → AC + BC 2AB →

puteri [66]

This is an incomplete question, here is a complete question.

For the net reaction: 2AB + 2C → A2 + 2BC, the following slow first steps have been proposed.

(1) AB → A + B

(2) 2C + AB → AC + BC

(3) 2AB → A₂ + 2B

(4) C + AB → BC + A

What rate law is predicted by each of these steps?

Answer : The rate law expression for the following reactions are:

(1) $\text{Rate}=k[AB]$

(2) $\text{Rate}=k[C]^2[AB]$

(3) $\text{Rate}=k[AB]^2$

(4) $\text{Rate}=k[C][AB]$

Explanation :

Rate law : It is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

The general reaction is:

$A+B\rightarrow C+D$

The general rate law expression for the reaction is:

$\text{Rate}=k[A]^a[B]^b$

where,

a = order with respect to A

b = order with respect to B

R = rate law

k = rate constant

$[A]$ and $[B]$ = concentration of A and B reactant

Now we have to determine the rate law for the given reaction.

(1) The balanced equations will be:

$AB\rightarrow A+B$

In this reaction, $AB$ is the reactant.

The rate law expression for the reaction is:

$\text{Rate}=k[AB]$

(2) The balanced equations will be:

$2C+AB\rightarrow AC+BC$

In this reaction, $C$ and $AB$ are the reactants.

The rate law expression for the reaction is:

$\text{Rate}=k[C]^2[AB]$

(3) The balanced equations will be:

$2AB\rightarrow A_2+2B$

In this reaction, $AB$ is the reactant.

The rate law expression for the reaction is:

$\text{Rate}=k[AB]^2$

(4) The balanced equations will be:

$C+AB\rightarrow BC+A$

In this reaction, $C$ and $AB$ are the reactants.

The rate law expression for the reaction is:

$\text{Rate}=k[C][AB]$

7 0

4 years ago

The effectiveness of nitrogen fertilizers depends on both their ability to deliver nitrogen to plants and the amount of nitrogen

densk [106]

Answer:

Ammonia > Urea > Ammonium nitrate > Ammonium sulphate

Explanation:

Percentage by mass of nitrogen in NH3:

Molar mass of NH3= 17 g/mol

Hence % by mass = 14/17 × 100 = 82.35%

% by mass of NH4NO3

Molar mass of NH4NO3 = 80.043 g/mol

Hence; 28/80.043 × 100 = 34.98%

% by mass of (NH4)2SO4;

Molar mass of (NH4)2SO4= 132.14 g/mol

Hence; 28/132.14 × 100 = 21.19%

% by mass of CH4N2O

Molar mass of urea = 60.0553 g/mol

Hence 28/60.0553 × 100 = 46.62%

8 0

3 years ago

A wave has a frequency of 3,5MHz and a wavelength of 85,5 m. What is the wave velocity through

Yuki888 [10]

Answer:

velocity = 29925×10⁶ m/s

Explanation:

Given data:

Frequency = 35 MHz

Wavelength = 855 m

Velocity = ?

Solution:

MHz to Hz

35×10⁶ Hz

Formula:

<em>velocity = Wavelength × Frequency</em>

velocity = 855 m × 35×10⁶ Hz

velocity = 29925×10⁶ m/s

Hz = s⁻¹

5 0

3 years ago