1. What is electromotive force?

2. How does it differ from the voltage deliver by a battery?

1. The intrinsic voltage capacity of a given battery.

2. Ther terminal voltage of a batter is the voltage that battery supplies across the circuit. It is found by calculating the drop in voltage across the battery due to its internal resistance and subtracting this from the electromotive force.

3. V= E -ir

3. A battery in a circuit has an electromotive force (E) and an internal resistance (r). The battery provides current (i) to the circuit. What is the terminal voltage (V)of the battery?

Sound of a known frequency, wavelength, intensity, and speed travels through air and bounces off an imperfect reflector which is moving toward the source. Which properties of sound remains the same before and after reflection?

Speed, intensity, frequency, or wavelength?

Speed.

Speed of sound is only affected by medium through which it travels. Since the wave is reflected off the moving surface (not refracted), the speed will not change.

Fill in the blank.

Atoms with a difference in electronegativity less than ___ form covalent bonds.

What bouyancy force does water exert on a lead weight that is completely submerged in the water?

volume of each lead weight = 4E^-6m³

density of water = 10³kg/m³

density of lead =1.13E⁴kg/m³

F= density of fluid *v*g

v=volume of fluid displaced=volume of object submerged

F= 4E^-2 N

PV =constant

P₁V₁=P₂V₂

P=pressure

V=volume

First law of thermodynamic?

What does a positive W mean?

delta U = Q-W

U=internal energy of object

Q= heat exchange

W= work done on or by the object

Positive W means work is done by the object. 

A balloon at the bottom of a water tank is allowed to rise freely to the surface. The air temperature inside the balloon decreases as the depth increases. Why would this be?

• Boyle's law tells us that the volume of the balloon must be increasing as the pressure decreases: P₁V₁=P₂V₂
• We know pressure is decreasing bc gauge pressure =density*g*z. z=depth. The greater the depth, the greater the pressure. 
• The bloon's volume is increasing, which means the gas inside the bloon is expanding so it's doing work. 
• Using first law of thermodynamics, one know that delta U = -W (since no heat is exchanged, Q is not considered in this equation).
• W is positive since work is done by the balloon. This means that delta U is negative. The balloon does work at the expense of its internal energy. 
• Since internal energy (U) is directly related to temp: U=(3/2)nRT, a decrease in internal energy results in a decrease of its temperature. 

Avogrado's constant?

(approx)

Fill in the blank with the correct color:

Litmus paper becomes ______ in acids and 

_________in bases

RED in acid

Blue in bases

True or False

A double displacement rxn is aka a metathesis rxn.

Name for a rxn that involves one compound that decomposes to two or more different compounds.

Oxidation reaction. 

REDOX (Reduction-Oxidation RXN)