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4 years ago

The term "periodic" helps identify __________ that occur in the table, like electronegativity or atomic radii.

Chemistry

1 answer:

Montano1993 [528]4 years ago

6 0

Answer:

option C= patterns

Explanation:

The periodic table is helpful to identify the element readily. All the elements are arranged properly. The elements with same physical and chemical properties are placed in same group and period. Periodic table is also helpful to predict the properties of those elements which are not discovered yet. This table is also very helpful to balance the chemical equations. The horizontal rows are called periods while vertical column are called groups. There are seven periods and eighteen groups are in periodic table.

Trends in periodic table:

As we move left to right in a period the atomic radius is decreases with increase of atomic number. The ionization energy goes to increases from left to right in period because of greater hold of nuclear charge on valance electron, so that's way more energy is required to overcome this charge and to make the atom ionic.

From left to right in period electron affinity and electronegativity also increases.

As we move top to bottom in group ionization energy decreases with increase of atomic number because of large atomic radius. The valance electron require less energy to move free. The electron affinity and electronegativity also decreases from top to bottom.

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66.667 mL of 3.000 M H2SO4 (aq) solution was neutralized by the stoichiometric amount of 4.000 M Al(OH)3 solution in a coffee cu

Alik [6]

Answer:

$\large \boxed{\Delta_{\textbf{r}}H =\text{-4600 J$\cdot$ mol}^{-1}}$

Explanation:

This is an unrealistic problem, because Al(OH)₃is highly insoluble in water.

There are two parts to this question:

A. Stoichiometry — in which we figure out the volumes, masses, and moles of products

B. Calorimetry — in which we calculate the enthalpy of reaction.

A. Stoichiometry

1. Calculate the volume of Al(OH)₃

(a) Balanced chemical equation.

2Al(OH)₃ + 3H₂SO₄ ⟶ Al₂(SO₄)₃+ 6H₂O

V/mL: 66.667

c/mol·L⁻¹: 4.000 3 .000

(b) Moles of H₂SO₄

$\rm \text{66.667 mL H$_{2}$}SO_{4} \times \dfrac{\text{3.000 mmol H$_{2}$SO}_{4}}{\text{1 mL H$_{2}$SO}_{4}} = \text{200.00 mmol H$_{2}$SO}_{4}$

(c). Moles of Al(OH)₃

The molar ratio is 2 mmol Al(OH)₃:3 mmol H₂SO₄

$\text{Moles of Al(OH)}_{3} = \text{200.00 mmol of H$_{2}$SO}_{4} \times \dfrac{\text{2 mmol Al(OH)}_{3}}{\text{3 mmol H$_{2}$SO}_{4}}\\\\= \text{133.33 mmol Al(OH)}_{3}$

(d). Volume of Al(OH)₃

$\text{Moles of Al(OH)}_{3} = \text{200.00 mmol of H$_{2}$SO}_{4} \times \dfrac{\text{1 mL Al(OH)}_{3}}{\text{4 mmol H$_{2}$SO}_{4}} = \text{50.000 mL Al(OH)}_{3}$

B. Calorimetry

There are two energy flows in this reaction.

q₁ = heat from reaction

q₂ = heat to warm calorimeter

q₁ + q₂ = 0

nΔH + mCΔT = 0

Data:

Moles of Al₂(SO₄)₃ = 0.066 667 mol

C = 1.10 J°C⁻¹g⁻¹

T_i = 22.3 °C

T_f = 24.7 °C

Calculations

(a) Mass of solution

Assume the solutions have the same density as water (unrealistic).

Mass of sulfuric acid solution = 66.667 g

Mass of aluminium hydroxide solution = <u> 50.000 </u>

TOTAL = 116.667 g

(b) ΔT

ΔT = T_f - Ti = 24.7 °C - 22.3 °C = 2.4°C

(c) ΔH

$\begin{array}{ccccl}n\Delta H & +& mC \Delta T& = &0\\\text{0.066 667 mol }\times \Delta H& + & \text{116.667 g} \times 1.10 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$} \times 2.4 \, ^{\circ}\text{C} & = & 0\\0.066667 \Delta H \text{ mol} & + & \text{310 J} & = & 0\\&&0.066667 \Delta H \text{ mol} & = & \text{-310 J} & & \\\end{array}\\$

$\begin{array}{ccccl}& &\Delta H & = & \dfrac{\text{-310 J}}{\text{0.066667 mol}}\\\\& &\Delta H & = & \textbf{-4600 kJ/mol}\\\end{array}\\\large \boxed{\mathbf{\Delta_{\textbf{r}}H} =\textbf{-4600 J$\cdot$ mol}^{\mathbf{-1}}}$

This is an absurd answer, but it's what comes from your numbers.

6 0

3 years ago

Will reward brainliest

Kazeer [188]

<span>Stratosphere. ...Mesosphere. ...Thermosphere. ...Ionosphere. ...<span>Exosphere.</span></span>

6 0

3 years ago

Read 2 more answers

A) How do you prepare %3 (w/v) Na2CO3 solution from Na2CO3⸱2H2O? (15p) Na2CO3 MW=106 g/mol

just olya [345]

Answer:

4.02g of Na2CO3⸱2H2O must be added completing the volume of the solution to 100mL

Explanation:

A 3%(w/v) solution contains 3g of solute (In this case, Na2CO3) in 100mL of solution.

Assuming we require 100mL of solution we must add 3g of Na2CO3. The reactant that is available is its dihydrate, with molar mass:

106g/mol + 2*MW H2O

106g/mol + 2*18g/mol = 142g/mol

That means the mass of Na2CO3.2H2O that must be added to prepare the solution is:

3g Na2CO3 * (142g/mol Na2CO3.2H2O / 106g/mol Na2CO3) =

<h3>4.02g of Na2CO3⸱2H2O must be added completing the volume of the solution to 100mL</h3>

8 0

3 years ago

In a water molecule the two unshared pairs of electrons on the oxygen cause the water molecule to have a _______ geometric shape

Luba_88 [7]

Answer:

1. Bent geometric shape

2. Polar molecule

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4 years ago

Not yet answered Points possible: 1.00 The equivalence point of any acid-base titration can be determined visually from a titrat

pshichka [43]

The volume of the base should be gradually increased, stopping once the equivalence point is achieved. At the volume halfway between the equivalence point and the acid, the acid's pKa is equal to the pH.

<h3>What is titration, for instance?</h3>

Titration, sometimes referred to as titrimetry, is a method for calculating the concentration of a specific analyte in a mixture that is used in chemical qualitative analysis. Titration, which is also sometimes referred to as volumetric analysis, is a crucial analytical chemistry method.

<h3>What governs titration in its basic form?</h3>

The following is the fundamental titration principle: The sample being studied is given a solution, referred to as a titrant or standard solution. A chemical is present in the titrant in a known concentration.

To know more about Titration visit:

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1 year ago