1. Để xác định hàm lượng H3PO4 người ta hút 5ml dung dịch cần xác định, hòa tan định mức thành 250ml. Lấy 10ml sau khi định mức, đem chuẩn trực tiếpvới NaOH 0,086N chỉ thị phenolphtalein. Thể tích NaOH tiêu tốn cho quá trình chuẩn độ là 15,75ml. Viết các phản ứng xảy ra ? Tính hàm lượng g/lit H3PO4 ?

If 0.414 g of hydrogen is obtained in this experiment how many grams of sulfur must be obtained

In a sample of oxygen gas at room temperature, the average kinetic energy of all the balls stays constant. which postulate of kinetic molecular theory best explains how this is possible? a. attractive forces between gas particles are negligible because the particles of an ideal gas are moving so quickly. b. collisions between gas particles are elastic; there is no net gain or loss of kinetic energy. c. gases consist of a large number of small particles, with a lot of space between the particles. d. gas particles are in constant, random motion, and higher kinetic energy means faster movement.

In which phase(s) do the molecules take the shape of the container?