Page 21 - Chemistry for Grade X

CHEMISTRY FOR GRADE X
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5. Jelaskan pengertian bahan kaustik, dan berikan contoh bahan kaustik minimal 2 !
6. Seorang murid menyiapkan 3 tabung reaksi yang masing-masing berisi 10 mL zat kimia
A. Ia kemudian menambahkan 1 mL zat kimia B ke dalam tabung pertama, 2mL ke dalam
tabung kedua, dan 3 mL ke dalam tabung ketiga. Selanjutnya ia mengukur pH (derajat
keasaman) dari zat kimia yang terbentuk. Dari penjelasan ini, tentukan variabel bebas,
variabel kontrol, dan variabel terikatnya !
7. Aseton merupakan suatu sat cair yang digunakan untuk pembersih cat kuku. Aseton
merupakan campuran yang terdiri dari 25% aseton dan 75% air. Jelaskan menurut
pendapatmu apakah aseton termasuk campuran homogen atau heterogen ?
8. Identify whether these matters are pure substance or mixture. Provide reasons for your
answer.
Matter Substance/mixture Reason

Table salt .... ....

Sugar .... ....

Petroleum .... ....

Soil .... ....

River water .... ....

9. An oil tanker that hits rocks causes an oil spill. The government put a lot of effort to clean
up the spill. However, during the process some seawater was also removed along with the
oil. What method can be used to separate the oil and seawater ?

10. Three students, Santi, Adit, and Rosa, weighed substances using ameasuring glass and an
electronic scale. The measurement was repeated three times and the results are given
below .

Measurement Santi Adit Rosa

I 10.1 g 11.0 g 9.5 g

II 10.2 g 10.9 g 10.5 g

III 10.0 g 11.2 g 10.0 g

Average ..... g ..... g ..... g

a. Calculate the average mass of the substances
b. Draw the information on a graphic
c. Who has the most precised information ?

KIMIA SEMESTER 1 KELAS X 21