Blog

AIRPORT NAME for “KGFK” [BLANK-1]

When Karl caveman adds chilled grog to his new granite mug, he removes 8.75 kJ of heat energy from the mug. If the mug has a mass of 825 g and was at 25oC initially, what is it’s new temperature? (The specific heat of granite is 0.79 J/g-oC.) 

What is the temperature at which a substance’s vapor pressure equals the external atmospheric pressure?

Use Hess’s law to determine the enthalpy of combustion (ΔH4, kJ/mol) of diborane (reaction 4 below) using reactions 1-3?        4.    B2H6(g) + 3O2(g)  →  B2O3(s) + 3H2O(g)        ΔH4 = ? kJ/mol given the following information:  2B(s) + 3H2(g) → B2H6(g)      ΔH1 = -36 kJ/mol  H2(g) + ½O2(g)  → H2O(l)      ΔH2 = −286 kJ/mol 2B(s) + 3⁄2O2(g) → B2O3(s)    ΔH3 = -1274 kJ/mol

The driver’s side steering wheel of a car contains 50.g of sodium azide in an airbag. Upon contact, sodium azide is rapidly heated (~20 ms) by metal filament prompting the reaction below. What is the inflation volume (L) of a typical airbag at 25.0oC at 0.961 atm pressure assuming ideal behavior?  2NaN3(s) + heat → 2 Na(s) + 3N2(g)

An aqueous solution is 1.55 molal in CuCl2 at 25oC.  What is the molarity of the CuCl2 solution at 25oC? (The density of the solution is 1.21 kg/L.) 

What is the mass, in grams, of 2.74 L of CO gas measured at 33°C and 945 mmHg?

What are the spectator ions in precipitation reaction below?  Na2S(aq) + ZnCl2(aq)  → ZnS(s) + 2NaCl(aq)

Appearance of a QRS complex immediately after a pacing spike indicates that what event has occurred?

Pacemaker generators use what type of batteries to create the electrical impulses?