What number should be placed in the blank to balance the equation 4fe + __O2 = 2Fe2O3

Which type of solute is present in aqueous solution predominantly as hydrated ions rather than as molecules?

Sound molecules can "stack up" in front of airplanes traveling at very high speeds. This can cause which of the following? A. Subsonic speeds B. Fire C. A combustion reaction D. Sonic booms

What is the definition of density?

What allows us to stand upright and keeps us from falling through the ground?

A confused student was doing an isomer problem and listed the following six names as different structural isomers of C7H16. a. 1-sec-butylpropane b. 4-methylhexane c. 2-ethylpentane d. 1-ethyl-1-methylbutane e. 3-methylhexane f.

How many molecules of sodium nitrate are produced when 17 g of sodium azide, NaN3, react according to the following equation: NaN3 (aq) + AgNO3 (aq) - --> AgN3 (s) + NaNO3 (aq) Question options: 3.7x1023 1.6 x 1023 1.85x1023 6.02x1023

Which statement is true for the given reaction? Zn + PbSO4

A student states the following: "Since acetone (nail polish remover) evaporate more readily than water, one would assume that acetone has weaker intermolecular forces than water." Evaluate their claim. (2 sentences)

A catalyst can only be used once. True False

On what basis do we distinguish between substances and separate them from one another?