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2 years ago

Complete the sentence. continental drift is the idea that...

1 answer:

7 0

States that all the continents were initially one large land mass, that split into the various continents after a long period of time.

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Using the mmoles of (35)-2,2,-dibromo-3,4-dimethylpentane calculated earlier and the molecular weight of the product (962 g/mol)

Sedbober [7]

Answer:

The yield of the product in gram is $\mathsf{{w_P}=0.26 \ gram}$

Explanation:

Given that:

the molecular mass weight of the product = 96.2 g/mol

the molecular mass of the reagent (3S)-2,2,-dibromo-3,4-dimethylpentane is 257.997 g

given that the millimoles of the reagent = 2,7 millimoles = $2.7 \times 10^{-3} \ moles$

We know that:

Number of moles = mass/molar mass

Then:

$2.7 \times 10^{-3} = \dfrac{ mass}{257.997}$

$mass = 2.7 \times 10^{-3} \times 257.997$

mass = 0.697

Theoretical yield = (number of moles of the product/ number of moles of reactant) × 100

i.e

Theoretical yield = $\dfrac{n_P}{n_R}\times 100\%$

where;

$n_P = \dfrac{w_P}{m_P}$ and $n_R = \dfrac{w_R}{m_R}$

Theoretical yield = $\dfrac{(\dfrac{w_P}{m_P})}{(\dfrac{w_R}{m_R})} \times 100\%$

Given that the theoretical yield = 100%

Then:

$100\% =\dfrac{(\dfrac{w_P}{m_P})}{(\dfrac{w_R}{m_R})} \times 100\%$

$\dfrac{w_P}{m_P}=\dfrac{w_R}{m_R}$

${w_P}=\dfrac{w_R \times m_P}{m_R}$

where,

$w_P$ = derived weight of the product

$m_P =$ the molecular mass of the derived product

$m_R =$ the molecular mass of the reagent

$w_R$ = weight in a gram of the reagent

${w_P}=\dfrac{w_R \times m_P}{m_R}$

${w_P}=\dfrac{0.697 \times 96.2}{257.997}$

$\mathsf{{w_P}=0.26 \ gram}$

8 0

2 years ago

A CaCl2 solution is given to increase blood levels of calcium. If a patient receives 6.1 mL of a 12 % (m/v) CaCl2 solution, how

Yuliya22 [10]

Mass of CaCl₂ = 0.732 g

<h3>Further explanation</h3>

The concentration of a substance can be expressed in several quantities such as moles, percent (%) weight / volume,), molarity, molality, parts per million (ppm) or mole fraction. The concentration shows the amount of solute in a unit of the amount of solvent.

$\tt \%(m/v)\rightarrow 12\%=\dfrac{mass~CaCl_2}{volume~of~solution}\times 100\%\\\\mass~CaCl_2=12\%\times 6.1\div 100\%\\\\mass~CaCl_2=0.732~g$

5 0

3 years ago

If acetic acid is the only acid that vinegar contains (ka=1.8×10−5), calculate the concentration of acetic acid in the vinegar.

kicyunya [14]

Ethanoic (Acetic) acid is a weak acid and do not dissociate fully. Therefore its equilibrium state has to be considered here.

$CH_{3}COOH \ \textless \ ---\ \textgreater \ H^{+} + CH_{3}COO^{-}$

In this case pH value of the solution is necessary to calculate the concentration but it's not given here so pH = 2.88 (looked it up)

pH = 2.88 ==> $[H^{+}]$ = $10^{-2.88}$ = 0.001 $moldm^{-3}$

The change in Concentration Δ $[CH_{3}COOH]$ = 0.001 $moldm^{-3}$

  CH3COOH H+ CH3COOH
Initial   $moldm^{-3}$      $x$ 0 0

Change $moldm^{-3}$ -0.001 +0.001 +0.001

Equilibrium $moldm^{-3}$ $x$ - 0.001 0.001 0.001


Since the $k_{a}$ value is so small, the assumption
$[CH_{3}COOH]_{initial} = [CH_{3}COOH]_{equilibrium}$ can be made.

$k_{a} = [tex]= 1.8*10^{-5} = \frac{[H^{+}][CH_{3}COO^{-}]}{[CH_{3}COOH]} = \frac{0.001^{2}}{x}$

Solve for x to get the required concentration.

note: 1.)Since you need the answer in 2SF don&t round up values in the middle of the calculation like I've done here.

2.) The ICE (Initial, Change, Equilibrium) table may come in handy if you are new to problems of this kind

Hope this helps!

8 0

3 years ago

If a solution has a pH of 2, what is the hydroxide ion concentration?

murzikaleks [220]

Answer:

Explanation:

14=pH + pOH

pOH= 14 - 2

pOH= 12

pOH= -log[OH]

[OH]= 10^-12

=1×10^-12

5 0

11 months ago

Using this equation, m1v2=m2v2 , calculate the diluted molarity of 100 mL of a 0.5 M solution when 50 mL of

geniusboy [140]

The molarity of the diluted solution is 0.33 M

From the question given above, the following data were obtained:

Molarity of stock solution (M₁) = 0. 5 M

Volume of stock solution (V₁) = 100 mL

Volume of diluted solution (V₂) = 100 + 50 = 150 mL

<h3>Molarity of diluted solution (M₂) =? </h3>

The molarity of the diluted solution can be obtained by using the dilution formula as illustrated below:

0.5 × 100 = M₂ × 150

50 = M₂ × 150

Divide both side by 150

M₂ = 50 / 150

Therefore, the molarity of the diluted solution is 0.33 M

Learn more: brainly.com/question/24625656

8 0

2 years ago