Answer is: 2. dillute acids feel slipper.
1) Acids are corrosive is correct. For example hydrochloric acid (HCl) will react with most metals.
2) Dillute acids feel slippery is not correct. Bases, for example solution of sodium hydroxide feels slipery.
3) Acids have a distinctly sour taste is correct. For example, vinegar is mixture of acetic acid (CH₃COOH) and water (H₂O). Vinegar is colourless liquid with sour taste and pungent smell, freezing point of the vinegar is lower than glacial acetic acid.
4) Acids have more hydronium ions than hydroxide ions is correct. Because acid gives a lot of hydrogen cations (H⁺), pH (pH = -log[H⁺]) is lower than seven (acidic solution).
Answer:
froth flotation is a technique commonly used in the mining industry. In this technique, particles of interest are physically separated from a liquid phase as a result of differences in the ability of air bubbles to selectively adhere to the surface of the particles, based upon their hydrophobicity.
Explanation:
Froth floatation method is commonly used to concentrate sulphide ore such as galena (PbS), zinc blende (ZnS) etc. (ii) In this method, the metaalic ore particles which are perferentially wetted by oil can be separated from gangue. (iii) In this method, the crushed ore is suspended in water and mixed with frothing agent such as pine oil, eucalyptus oil etc. (iv) A small quantity of sodium ethyl xanthate which act as a collector is also added. (v) A froth is generated by blowing air through this mixture. (vi) The collector molecules attach to the ore particles and make them water repellent. (vii) As a result, ore parrticles, wetted by the oil, rise to the surface along with the froth. (viii) The froth is skimmed off and dried to recover the concentration ore. (ix) The gangue particles that are preferentially wetted by water settle at the bottom.
The answer is A: Between 50 and 5,000 amino acids
