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3 years ago

How can we explain patterns of behavior among chemical elements?

2 answers:

5 0

The periodic table helps us see the pattern of behavior of elements. The chemical and physical properties of elements can be estimated based on their position in the periodic table.

Oduvanchick [21]3 years ago

4 0

Patterns of behavior among chemical elements can be explained using the periodic table. In the periodic table, chemical elements are arranged according to their proton numbers,(atomic number) this organisation illustrates common recurring patterns of physical and chemical properties among the elements.

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Balance this equation- Na3PO4 + KOH -> NaOH + K3PO4

SSSSS [86.1K]

Na3PO4 + 3 KOH = 3 NaOH + K3PO4

3 0

2 years ago

Read 2 more answers

One crystalline form of silica (SiO2) has a cubic unit cell, and from X-ray diffraction data it is known that the cell edge leng

tigry1 [53]

Answer:

There are 8Si atoms and 16 O atoms per unit cell

Explanation:

From the question we are told that:

Edge length $l=0.700nm=>0.7*10^9nm$

Density $\rho=2.32g/cm^3$

Generally the equation for Volume is mathematically given by

$V=l^3$

$V=(0.7*10^9)m^3$

$V=3,43*10^-{22}cm$

Where

Molar mass of (SiO2) for one formula unit

$M=28+32$

$M=60g/mol$

Therefore

Density of Si per unit length is

$\rho_{si}=\frac{9.96*10^{23}}{3.43*10^22}$

$\rho=0.29$

Molar mass of (SiO2) for one formula unit

$M=28+32$

$M=60g/mol$

Therefore

There are 8Si atoms and 16 O atoms per unit cell

6 0

3 years ago

To prepare an acetic acid/acetate buffer, a technician mixes 30.6 mL of 0.0880 acetic acid and 21.6 mL of 0.110 sodium acetate i

enyata [817]

Answer: There are 0.00269 moles of acetic acid in buffer.

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution in ml}}$ .....(1)

Molarity of acetic acid solution = 0.0880 M

Volume of solution = 30.6 mL

Putting values in equation 1, we get:

$0.0880M=\frac{\text{Moles of acetic acid}\times 1000}{30.6ml}\\\\\text{Moles of acetic acid}=\frac{0.0880\times 30.6}{1000}=0.00269mol$

Thus there are 0.00269 moles of acetic acid in buffer.

8 0

2 years ago

For the reaction co(g)+2h2(g)<->ch3oh(g) at 700. k, equilibrium concentrations are [h2] = 0.072 m, [co] = 0.020 m, and [ch

SVETLANKA909090 [29]

The balanced equation for the reaction is
CO(g) + 2H₂(g) ⇄ CH₃OH(g)

Since given concentrations are at equilibrium state, the expression for the equilibrium constant, k can be written as
k = [CH₃OH(g)] / [CO(g)] [H₂(g) ]²

By substitution,
k = 0.030 M / 0.020 M x (0.072 M)²
k = 289.35 M⁻²

6 0

3 years ago

A catalyst decreases the activation energy of a particular exothermic reaction by 34 kJ/mol, to 57 kJ/mol. Assuming that the mec

vagabundo [1.1K]

Answer:

the activation energy for the uncatalyzed reverse reaction is 83kJ/mol

Explanation:

see the attached file

4 0

3 years ago