8. Which describes the reaction of a substance to form one or more new

substances

A a chemical change

B a physical change

C a change of state

You wish to prepare an hc2h3o2 buffer with a ph of 4.34. if the pka of is 4.74, what ratio of c2h3o2/hc2h3o2 must you use?

What volume will 50.2 grams of co2 (g) occupy at stp?

Ions of the elements oxygen (O), sulfur (S), and selenium (Se) usually have charges of 2-. Ions of the elements fluorine (F), chlorine (Cl), and bromine (Br) usually have charges of 1-.

What mass of magnesium would combine with exactly 16.0 grams of oxygen

Molecules and electromagnetic radiation interact. atoms may dissociate, a molecule may rotate, or bonds may stretch and bend. carbon dioxide has four possible vibrations. select the true statements about the vibrations below.

Magnesium and calcium have similar chemical properties because a magnesium atom and a calcium atom have the same (1) atomic number (2) mass number (3) total number of electron shells (4) total number of valence electrons

Which properties change the composition of a substance? Physical properties Neither chemical nor physical properties Chermical and physical properties Chemical properties

A seismograph uses a ... to record drums vibration

The volume of a gas is 36.0 ml at 10.0°c and 4.50 atm. at what temperature (°c) will the gas have a pressure of 3.50 atm and a volume of 85.0 ml?

Velocity is the slope of the acceleration vs. time graph. O A. True False