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2 years ago

How many atoms are in 2.3 moles Au?

Chemistry

2 answers:

Vaselesa [24]2 years ago

6 0

Answer:

6.02×10^23atoms of au

max2010maxim [7]2 years ago

6 0

Answer:

i think 3

Explanation:

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Periodic table the first row of elements fits in the period blank after the element blank the second row of elements fits in per

Bezzdna [24]

Answer:

The first row fits in period 2

The second row fits in period 3

Explanation:

Elements arranged vertically in the periodic table in groups that share similar chemical properties.

Elements are also organized horizontally in rows or periods

The length of each period is determined by the number of electrons that can occupy the sublevels being filled in that period.

7 0

2 years ago

If 90.0 grams of ethane reacted with excess chlorine,how many grams of dicarbon hexachloride would form

tigry1 [53]

Answer:

709 g

Step-by-step explanation:

a) Balanced equation

Normally, we would need a balanced chemical equation.

However, we can get by with a partial equation, as log as carbon atoms are balanced.

We know we will need an equation with masses and molar masses, so let’s gather all the information in one place.

M_r: 30.07 236.74

C₂H₆ + … ⟶ C₂Cl₆ + …

m/g: 90.0

(i) Calculate the moles of C₂H₆

n = 90.0 g C₂H₆ × (1 mol C₂H₆ /30.07 g C₂H₆)

= 2.993 mol C₂H₆

(ii) Calculate the moles of C₂Cl₆

The molar ratio is (1 mol C₂Cl₆/1 mol C₂H₆)

n = 2.993 mol C₂H₆ × (1 mol C₂Cl₆/1 mol C₂H₆)

= 2.993 mol C₂Cl₆

(iii) Calculate the mass of C₂Cl₆

m = 2.993 mol C₂Cl₆ × (236.74 g C₂Cl₆/1 mol C₂Cl₆)

m = 709 g C₂Cl₆

The reaction produces 709 g C₂Cl₆.

6 0

2 years ago

A buffer solution contains 0.306 M C6H5NH3Br and 0.418 M C6H5NH2 (aniline). Determine the pH change when 0.124 mol HCl is added

Ulleksa [173]

Answer: The pH change of the buffer is 0.30

Explanation:

To calculate the pH of basic buffer, we use the equation given by Henderson Hasselbalch:

$pOH=pK_b+\log(\frac{[\text{conjugate acid}]}{[\text{base}]})$

$pOH=pK_b+\log(\frac{[C_6H_5NH_3^+]}{[C_6H_5NH_2]})$ .....(1)

We are given:

$pK_b$ = negative logarithm of base dissociation constant of aniline = 9.13

$[C_6H_5NH_3^+]=0.306M$

$[C_6H_5NH_2]=0.418M$

pOH = ?

Putting values in equation 1, we get:

$pOH=9.13+\log(\frac{0.306}{0.418})\\\\pOH=8.99$

To calculate pH of the solution, we use the equation:

$pH+pOH=14\\pH_{initial}=14-8.99=5.01$

To calculate the molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles hydrochloric acid solution = 0.124 mol

Volume of solution = 1 L

Putting values in above equation, we get:

$\text{Molarity of HCl}=\frac{0.124}{1L}\\\\\text{Molarity of HCl}=0.124M$

The chemical reaction for aniline and HCl follows the equation:

$C_6H_5NH_2+HCl\rightarrow C_6H_5NH_3^++Cl^-$

Initial: 0.418 0.124 0.306

Final: 0.294 - 0.430

Calculating the pOH by using using equation 1:

$pK_b$ = negative logarithm of base dissociation constant of aniline = 9.13

$[C_6H_5NH_3^+]=0.430M$

$[C_6H_5NH_2]=0.294M$

pOH = ?

Putting values in equation 1, we get:

$pOH=9.13+\log(\frac{0.430}{0.294})\\\\pOH=9.29$

To calculate pH of the solution, we use the equation:

$pH+pOH=14\\pH_{final}=14-9.29=4.71$

Calculating the pH change of the solution:

$\Delta pH=pH_{initial}-pH_{final}\\\\\Delta pH=5.01-4.71=0.30$

Hence, the pH change of the buffer is 0.30

8 0

2 years ago

How many moles of Al are needed to react completely with 1.2 moles of Fe0

DIA [1.3K]

0.8 moles

3 moles of feO gives you 2 moles of Al and 1.2 of your moles should give you 1.2 divided by 3*2 so it equals 0.80 moles

Right?

7 0

2 years ago

You were asked to determine the identity of an unknown liquid and can measure only one physical property. you heat the liquid an

Butoxors [25]

I did this before and i had got an A no it but its been along time tho

7 0

3 years ago