If you travel 7.5 km and walk for 1.5 h, what is your average speed? <br> Show your work?

Tim and Jim finished their lab experiment earlier than their classmates. What should they do while they wait for the others to f

Alisiya [41]

The answer to your question is,

C. Look over their answers to the lab questions and check for errors.

-Mabel <3

3 0

4 years ago

determine the empirical and molecular formula of a compound composed of 18.24 g carbon, 0.51 g hydrogen, and 16.91 g fluorine an

Vika [28.1K]

Answer: The empirical formula for the given compound is $C_3HF_2$ and molecular formula for the given compound is $C_{24}H_8F_{16}$

Explanation : Given,

Mass of C = 18.24 g

Mass of H = 0.51 g

Mass of F = 16.91 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{18.24g}{12g/mole}=1.52moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{0.51g}{1g/mole}=0.51moles$

Moles of Fluorine = $\frac{\text{Given mass of Fluorine}}{\text{Molar mass of Fluorine}}=\frac{16.91g}{19g/mole}=0.89moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.51 moles.

For Carbon = $\frac{1.52}{0.51}=2.98\approx 3$

For Hydrogen = $\frac{0.51}{0.51}=1$

For Fluorine = $\frac{0.89}{0.51}=1.74\approx 2$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H : F = 3 : 1 : 2

The empirical formula for the given compound is $C_3H_1F_2=C_3HF_2$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{molecular mass}}{\text{empirical mass}}$

We are given:

Molar mass = 562.0 g/mol

Mass of empirical formula = 3(12) + 1(1) + 2(19) = 75 g/eq

Putting values in above equation, we get:

$n=\frac{562.0}{75}=7.49\approx 8$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_3HF_2=(C_3HF_2)_n=(C_3HF_2)_8=C_{24}H_8F_{16}$

Thus, the molecular formula for the given compound is $C_{24}H_8F_{16}$

8 0

3 years ago

For a multistep reaction the observed order of

Mkey [24]

Answer: 3 slowest reaction of the squence

Explanation:

4 0

3 years ago

What is the formula for copper(ii) phosphate??

Ilia_Sergeevich [38]

It would be Cu3(PO4)2

6 0

3 years ago

Si tenemos una solución de ácido láctico 0.025M con un pH = 2.75. ¿Cuál es la constante de equilibrio Ka?

rodikova [14]

Answer:

La constante de equilibrio Ka del ácido láctico es 1.38x10⁻⁴.

Explanation:

El ácido láctico es un ácido débil cuya reacción de disociación es la siguiente:

CH₃CHOHCOOH + H₂O ⇄ CH₃CHOHCOO⁻ + H₃O⁺ (1)

0.025M - x x x

La constante de acidez del ácido es:

$Ka = \frac{[CH_{3}CHOHCOOH^{-}][H_{3}O^{+}]}{[CH_{3}CHOHCOOH]}$

Sabemos que la concentración del ácido inicial es:

[CH₃CHOHCOOH] = 0.025 M

Y que a partir del pH podemos hallar [H₃O⁺]:

$pH = -log[H_{3}O^{+}]$

$[H_{3}O^{+}] = 10^{-pH} = 10^{-2.75} = 1.78 \cdo 10^{-3} M$

Debido a que el ácido se disocia en agua para producir los iones CH₃CHOHCOO⁻ y H₃O⁺ de igual manera (según la reacción (1)), tenemos:

[CH₃CHOHCOO⁻] = [H₃O⁺] = 1.78x10⁻³ M

Y por esa misma disociación, la concentración del ácido en el equilibrio es:

$[CH_{3}CHOHCOOH^{-}] = 0.025 M - 1.78 \cdo 10^{-3} M = 0.023 M$

Entonces, la constante de equilibrio Ka del ácido láctico es:

$Ka = \frac{[CH_{3}CHOHCOOH^{-}][H_{3}O^{+}]}{[CH_{3}CHOHCOOH]} = \frac{(1.78 \cdo 10^{-3})^{2}}{0.023} = 1.38 \cdot 10^{-4}$

Espero que te sea de utilidad!

3 0

3 years ago

If you travel 7.5 km and walk for 1.5 h, what is your average speed? Show your work?