Concentración de Disoluciones en % (Solucionario)

Ejercicio 1.  x% en masa = 25 g : 300 g · 100 = 8,3 %

Ejercicio 2.  2% en masa = x : 25 g · 100 = 0’5 g

Ejercicio 3.  x% en masa = 56 g : 365 g · 100 = 15,7%

Ejercicio 4.  x% en masa = 5 g : 200 g · 100 = 2,5 % 

Ejercicio 5. Para poder decidir, calculamos el porcentaje en masa de la B primero: sumamos los aditivos 350 + 50 = 400 g

x% en masa = 50 g : 400 g · 100 = 12,5 %

La opción A contiene más porcentaje en masa que la opción B.

Ejercicio 6.  x % en masa = 80 g : 880 g · 100 = 9,1 %

Ejercicio 7.  12 % en masa = x : 75 cL · 100 = 9 cL

Ejercicio 8.  25 % en masa = x : 250 mL · 100 = 62,5 mL

Ejercicio 9.     x % en masa = 147 g : 465 g · 100 = 31,6 g

Ejercicio 10.  8 % en masa = x : 18 g · 100 = 1,44 g

Ejercicio 11. 36 % en masa = x : 361  mL · 100 = 129,96 mL

Concentración de disoluciones (Solucionario)

Ejercicio 1. La concentración de la disolución preparada es la siguiente:  20 g/L

Ejercicio 2. La concentración necesaria es: 250 g/L

Ejercicio 3. La masa de soluto necesaria es: 2,5 g

Ejercicio 4. La masa necesarias es: 3’6 g

Ejercicio 5. La concentración necesaria es: 666,6 g/L

Ejercicio 6. La concentración de la disolución es: 16,6 g/L

Ejercicio 7. La concentración es: 28’57 g/L

Ejercicio 8. La cantidad de soluto es: 3’75 g

Ejercicio 9. La cantidad de soluto necesaria es:  75 g

Ejercicio 10.

a) La concentración es:  66,6 g/L

b) La cantidad de azúcar debe ser 50 g.

Ejercicio 11. La cantidad de cloruro es: 4,5 g

Operaciones con Notación Científica (Solucionario)

 Ejercicio 1. Realiza las siguientes operaciones con notación científica:

Ejercicio 2. Calcula, expresando el resultado en notación científica:

Ejercicio 3. Expresa en notación científica y calcula, expresando el resultado también en notación científica:

Ejercicio 4. Efectúa y expresa el resultado en notación científica:

Notación Científica (Solucionario)

Ejercicio 1. Escribe en notación científica los siguientes números e indica su orden de magnitud:

Ejercicio 2. Escribe en forma decimal los siguientes números:

Ejercicio 3. Indica el orden de magnitud de las siguientes medidas y expresa el resultado en forma decimal y en notación científica en el caso de que no lo estuviera:

Factores de Conversión (Solucionario)

Ejercicio 1. Expresa en unidades del Sistema Internacional utilizando factores de conversión (SIMPLE):

Ejercicio 2. Expresa en las unidades del Sistema Internacional propuestas utilizando factores de conversión (SIMPLE):

Ejercicio 3. Expresa en unidades del Sistema Internacional utilizando factores de conversión (COMPUESTAS):

Problemas de Fracciones (Solucionario)

1. Me quedan 180 páginas.

2. Se pueden llenar 40 botellas.

3. El padre mide 1.92 m

4. En el bidón había 30 L

5. Soluciones:

• Sacaron sobresaliente 2 personas
• Suspendieron 12 personas

6. Un bote tenía 33 canicas y el otro 55

7. Tenía 133 €

8. Se pueden llenar 15 frascos

9. Soluciones:

• Tiene de arroz 104 g
• De cada cereal hay: 280 trigo, 216 g avena

10. Los libros de historia representan los 7/30

11. Soluciones:

• Pepita se come 15/35
• Quedan 10/35

12. Se obtienen 12 Kg

13. La capacidad del depósito es 3000 L

14.La anchura del campo mide 40 m

15. Quedan 50 L

16. Van los dos igual

17. El hijo tarda 3 h

18. El desagüe tarda 12 h

19. Su capacidad es 10 L

20. Soluciones:

• Se recaudó 345.6 total
• A las verduras corresponde 57.6 €

21. La capacidad total es 4 961 L

22. Al principio había 10 096 €

23. Debe recorrer 480 Km

24. Al principio había 540 L

25. En la cesta habían 375 manzanas

26. Soluciones:

• Pago 120 el primer plazo; 196 € el segundo y 124 el tercero.
• Me queda por pagar 100 €

27. El total de la herencia es 27 562.5 €

28. Metieron 100 goles

29. La superficie total es 510 h

30. El importa de cada plazo es de 162.5 cada plazo

Soluciones. Pasado Simple.

 EXERCISES

1. Complete the sentences with the pairs of verbs below. Use the Past simple affirmative.

• Vasco da Gama, a Portuguese explorer, sell  from Portugal in 1497. He reached India in 1498.

• Ray Tomlimson invented email in 1971. He sent an e-mail to his friends to tell them.

• Peter Skyllberg survived for two month in his car after a snowstorm. He ate snow to stay alive!

• In Australia, a family dog called River fought a snake and saved two young girls.

• In 2000, Prince William volunteered in Chile. He taught English in schools.

2. Put one of these verbs in each sentence:

Hurt teach       spend throw       fall      catch   buy   cost

• Tom’s father taught him how to drive when he was 17.

• Don fell down the stairs this morning and hurt his leg.

• We needed some money, so we bought our car.

• Ann spent a lot of money yesterday. She bought a dress that cost $80.

• Jim threw the ball to Sue, who caught it.

3. Write questions. A friend has just come back from vacation and you are asking about it.

• How long / stay there? How long did you stay there?

• Stay in a hotel? Did you stay in a hotel?

• Go alone? Did you go alone?

• How/ travel? How did you travel?

• The weather / nice ? Was the weather nice?

• Meet any interesting people? Did you meet any interesting people?

4. Put the verb into the correct form. Use the simple past.

• Tom didn’t go to work yesterday because wasn’t well.

• We didn’t eat anything because we weren't hungry.

• I didn’t rush because I wasn't hungry.

• She wasn't interested in the book because she didn’t understand it.

Ojo! Cuando queremos escribir una frase con el verbo TO BE en pasado de forma negativa, no debemos utilizar el auxiliar DIDN´T, debemos utilizar el verbo TO BE en pasado: “weren't” o “wasn't”

5. Write the simple past forms of the verbs:
   

Drive drove

Eat ate

Give gave

Go went

Know knew

Live lived

Play played

See saw

Sing sang

Sit sat

Study studied

Talk talked

Teach taught

Walk walked

Want wanted

Volunteer volunteered

Save saved

Invent invented

Send sent

Sail sailed

Reach reached

Survive survived

Fall fell

Wait waited

Have had

Improve improved

Know knew

Use used

Climb climbed

Fight fought

6.      Complete the sentences. Use the past simple affirmative of the verbs in the box.

Dance go have      listen to   meet     phone   say   watch

• He met an old friend, Denise.

• Paul and Denise listened to some excellent music.

• They danced all night.

• Paul phoned his family at midnight.

• He said ”Happy New Year!”.

• Paul and Denise watched the sunrise.

• They had a really good time.

7. Complete the sentences with the verbs in brackets in Past Simple.

• On 26th April 2003, Aron Ralston went hiking in Bluejohn Canyon in the USA.

• A 360 – kilogram rock fell on his arm.

• Ralston waited for many hours, but there weren't any people around to help him.

• He was hungry and thirsty because he didn’t have much food or water.

• His condition didn’t improve and he didn’t know how to scape.

•  After five days, he used his knife to cut off his own arm!

• With only one arm, Ralston climbed out of the canyon and survived his terrible accident!

8. Put the words in the correct order.

• Did/ when / go / ? / you  When did you go?

• Go / did / with your parents / ? / you  Did you go with your parents?

• To the museum? / your dad / did / drive  Did you drive to the museum?

• You / did / see /anything interesting?  Did you see anything interesting?

• Did/ how long / stay? / you  How long did you stay?

• Leave? / did / you/ what time  What time did you leave?

• You / like / did/ it?  Did you like it?

• Buy?/ what / you / did   What did you buy?

9. Complete the sentences using the verbs in the box and the past Simple.

Take feel have put see  say make  leave steal

• Somebody stole Dan’s bag.

• Dan felt embarrassed.

• John came into the classroom. He had TWO bags.

• Dan put his bag on the desk.

• Dan returned and saw his bag wasn’t on the desk.

• John said, “Hi Dan, made a mistake. Our bags are the same and I took yours. Sorry!

• He left the classroom.

• Dan said, “Where is my bag? Who took my bag?”

10. Complete the text with the verbs in brackets. Use the correct form of the Past Simple.

The first Newspaper

How did people get news before the invention of the newspaper? Did they hear the news in other ways? Thousands of years ago, many people never went to school, so they knew how to read or write. They met on the streets or in the center of town and they told each other about the news. Then, in 59 BC, the Romans created the first newspaper, but they sold it to people. They put it in different places around town. People readed the newspaper at those places and learned about battle and other important news of the day.