5. Thomson's experiments with cathode rays led to the discovery of the: electron Neutron

Why does a chemical equation have to be balanced

Anton [14]

The chemical equation needs to be balanced so that it follows the law of conservation of mass.

5 0

3 years ago

A car at rest ends accelerates for 12 seconds. After this time the car is going 36 m/s. What was its acceleration?

Zigmanuir [339]

Acceleration is defined as velocity per unit time.

$Acceleration=\frac{Velocity}{time}$

$a=\frac{dv}{dt}$

Here, a=acceleartion,

v=velocity=36 m/s

t=time=12 s

$a=\frac{dv}{dt}$

$a=\frac{36}{12}$

$a=3 ms⁻²$

A car at rest ends accelerates for 12 seconds. After this time the car is going 36 m/s. So acceleration that is a=3 ms⁻².

4 0

3 years ago

Read 2 more answers

An astronomer observes an asteroid in the solar system. He notes that the asteroid is three times farther from the Sun than Eart

ozzi

Answer:

3 AU

Explanation:

The distance from the Earth to the Sun is known as 1 AU, or 1 Astronomical Unit. If an asteroid is three times this distance, it is 3 AU away.

7 0

3 years ago

La aspirina se prepara haciendo reaccionar ácido salicílico con exceso de anhídrido etanoico. En un experimento, 50.05 g de ácid

Tanya [424]

La aspirina se prepara haciendo reaccionar ácido salicílico con exceso de anhídrido etanoico. En un experimento, 50.05 g de ácido salicílico se convirtieron en 55.45 g de aspirina. ¿Cuál fue el porcentaje de rendimiento?

In English:

Aspirin is prepared by reacting salicylic acid with excess ethanoic anhydride. In one experiment, 50.05 g of salicylic acid was converted to 55.45 g of aspirin. What was the yield percentage?

Answer:

el rendimiento porcentual para la cantidad dada de ácido salicílico es 84.99 %

In English:

the percent yield for the given amount of salicylic acid is 84.99%

Explanation:

La ecuación química equilibrada para la reacción se puede escribir como:

C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + HC₂H₃O₂

Para la reacción mostrada arriba; El reactivo limitante de la reacción es el ácido salicílico. Ahora; calcular el porcentaje de rendimiento; se espera que primero determinemos el rendimiento teórico de la reacción.

Entonces; la fórmula para calcular el porcentaje de rendimiento: $\mathbf {= \frac{actual \ yield }{theoretical \ yield } *100 }$

El rendimiento teórico se determina de la siguiente manera:

50.05 g * 1 mol / 138.21 g / mol de C₇H₆O₃ * 1 mol de C₉H₈O₄ / 1 mol de C₇H₆O₃ * 180.157 g / mol de C₉H₈O₄ = 65.24 g de C₉H₈O₄

Porcentaje de rendimiento $\mathbf {= \frac{55.45 }{65.24 } *100 }$

Porcentaje de rendimiento = 84.99%

Por lo tanto, el porcentaje de rendimiento para la cantidad dada de ácido salicílico es 84.99%

In English:

The balanced chemical eqaution for the reaction can be written as:

C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + HC₂H₃O₂

For the reaction shown above; The limiting reactant from the reaction is salicylic acid. Now; to calculate the percentage yield ; we are expected to first determine the theoretical yield of the reaction.

So; the formula for calculating the percentage yield $\mathbf {= \frac{actual \ yield }{theoretical \ yield } *100 }$

The theoretical yield is determined as follows:

50.05 g * 1 mol/ 138.21 g/mol of C₇H₆O₃ * 1 mol of C₉H₈O₄/ 1 mol of C₇H₆O₃ * 180.157 g/mol of C₉H₈O₄ = 65.24 g of C₉H₈O₄ is produced

Percentage yield $\mathbf {= \frac{55.45 }{65.24 } *100 }$

Percentage yield = 84.99%

Thus, the percent yield for the given amount of salicylic acid is 84.99%

7 0

4 years ago

As part of your job you are asked to make 1 liter of a 0.5 molar sucrose solution. how much sucrose (c12h22o11) do you need? use

kakasveta [241]

Answer:- 171 g

Solution:- It asks to calculate the grams of sucrose required to make 1 L of 0.5 Molar solution of it.

We know that molarity is moles of solute per liter of solution.

If molarity and volume is given then, moles of solute is molarity times volume in liters.

moles of solute = molarity* liters of solution

moles of solute = 0.5*1 = 0.5 moles

To convert the moles to grams we multiply the moles by molar mass.

Molar mass of sucrose = 12(12) + 22(1) + 11(16)

= 144 + 22 + 176

= 342 grams per mol

grams of sucrose required = moles * molar mass

grams of sucrose required = 0.5*342 = 171 g

So, 171 g of sucrose are required to make 1 L of 0.5 molar solution.

6 0

3 years ago