Is turning on a light bulb a physical and chemical change?

What type of reaction is Zn + 2HCl > ZnCl2 + H2

Using the following values of pKb, select the strongest acid from those listed in the answers. a. C5H5N (pKb = 8.75) b. N2H4 (pKb = 5.77) c. C6H5NH2 (pKb = 9.37) d. NH3 (pKb = 4.75) e. C2H5NH2 (pKb = 3.19)

The air in a hot-air balloon at 763 torr is heated from 14.0°C to 31.0°C. Assuming that the moles of air and the pressure remain constant, what is the density of the air at each temperature? (The average molar mass of air is 29.0 g/mol.)

A 430. ML solution of 0.230 M HBr (aq) is mixed with a solution of 225 mL of 0.350 M HClO4 (aq). How many moles of H + (aq) are present in the final solution?

Which tide occurs during a full or new Moon and is characterized by an extra-high tide caused by the straight-line arrangement of the Sun, Moon, and Earth? A. low B. neap C. spring

A 25 mL sample of 0.100 M HNO3 completely reacts with NaOH according to this equation: HNO3 (aq) + NaOH (aq) → NaNO3 (aq) + H2O (1) How many moles of HNO3 are in the sample?

What does diatonic means

A general term for an attractive force that holds two atoms together is known as an

Which law is known as the law of action-reaction

7. A 2.0 L container had 0.40 mol of He (g) and 0.60 mol of Ar (g) at 25°C. Which gas has a greater average kinetic energy? Which gas is traveling at a higher average speed? If Ar has an average speed of 431 m/s, what is the average speed of He?