Câu 8. Cho dãy các chất : Ca(HCO3)2 , NH4Cl , (NH4)2CO3 , ZnSO4 , Al(OH)3 , Zn(OH)2 .Số chất trong dãy có tính lưỡng tính là : A. 5 B. 4 C. 3 D. 2

If 10.5 l of a at 0.98to 1.50 , is ?

High-pressure liquid chromatography (hplc) is a method used in chemistry and biochemistry to purify chemical substances. the pressures used in this procedure range from around 500 kilopascals (500,000 pa) to about 60,000 kpa (60,000,000 pa). it is often convenient to know the pressure in torr. if an hplc procedure is running at a pressure of 1.03×108 pa , what is its running pressure in torr?

Amatch has about 21 milligrams of red phosphorus coating the tip. how many atoms of phosphorus is this?