Soal Ulangan Harian Koloid

Explanation
The given answer states that the colloid system cannot be separated by a normal filter but can be separated by an ultrafilter. This is because colloid particles have a diameter smaller than 0.1 mµ, which is too small to be filtered out by a normal filter. However, an ultrafilter has smaller pores that can trap and separate these small particles, allowing the colloid system to be separated. Additionally, the other properties mentioned, such as rapid sedimentation when left undisturbed and the ability to conduct electricity, are not relevant to the separation of the colloid system.

Explanation
Air laut merupakan sistem koloid karena terdiri dari partikel-partikel kecil yang terdispersi di dalam medium cair. Partikel-partikel tersebut terdiri dari garam, mineral, organisme kecil, dan bahan-bahan lain yang terlarut dalam air laut. Sistem koloid terbentuk ketika partikel-partikel tersebut tidak larut sepenuhnya dalam air laut dan tetap terdispersi di dalamnya. Oleh karena itu, air laut merupakan sistem koloid.

Explanation
When agar-agar powder is mixed with water and cooked, it forms a gel-like substance when it cools down. This indicates that the dispersed phase (agar-agar) is in solid form, and the dispersing medium (water) is able to form a stable colloidal system. Therefore, the correct classification for this system is "Emulsi Padat" or solid emulsion.

Explanation
A sol is a type of colloid where the dispersed phase is solid and the dispersing medium is liquid. In a sol, solid particles are finely dispersed and dispersed throughout the liquid medium. This allows for a stable suspension of solid particles in liquid. Sol is different from emulsion, aerosol, and foam, as they involve different combinations of dispersed and dispersing phases.

Explanation
The correct answer is 2,4. This is because the process of dispersing colloids involves two steps mentioned in the answer choices. Step 2 involves the introduction of air into the H2S solution, which helps in the dispersion of the colloidal particles. Step 4 involves adding AlCl3 solution to the precipitate of Al(OH)3, which leads to the formation of a colloidal solution. Therefore, the combination of steps 2 and 4 is the correct explanation for the method of colloid production by dispersion.

Explanation
The statement is correct because the process of making tofu involves coagulating the soy milk using a coagulant, such as gypsum or nigari, which causes the proteins in the soy milk to form curds. This coagulation process is essential in the production of tofu, as it helps to give tofu its characteristic texture and structure.

Explanation
Jawaban yang benar adalah "Salah". Susu tidak akan membentuk koloid hidrofob jika didispersikan dalam air. Sebaliknya, susu akan membentuk koloid hidrofilik karena partikel lemak dalam susu akan terdispersi dengan baik dalam air. Koloid hidrofob terbentuk ketika partikel-partikel nonpolar terdispersi dalam medium polar, seperti minyak dalam air.

Explanation
The given statement is correct. It states that the scattering of light by a colloidal system is called the Tyndall effect. The Tyndall effect occurs when light passes through a colloidal solution or suspension and is scattered by the dispersed particles. This phenomenon is used to distinguish between a true solution and a colloidal solution, as the Tyndall effect is not observed in true solutions where the particles are smaller and do not scatter light.