Answer:
the us and the soviet union
Explanation:
Answer: Explanation: Speed is simply velocity without a specified direction (speed is the magnitude of the velocity vector). Regardless of the two measurements, they both relate distance to time, but are slightly different. Instantaneous speed is the derivative of the total distance covered with respect to time.
Explanation: I hope this helps!
Answer:
The volume of the gas sample at standard pressure is <u>819.5ml</u>
Explanation:
Solution Given:
let volume be V and temperature be T and pressure be P.
1 torr= 1 mmhg
42.2 torr=42.2 mmhg
so,
Now
firstly we need to find the pressure due to gas along by subtracting the vapor pressure of water.
=735-42.2=692.8 mmhg
Now
By using combined gas law equation:
Here 
are standard pressure and temperature respectively.
we have
Substituting value, we get
corrected question: A chemist adds 135mL of a 0.21M zinc nitrate solution to a reaction flask. Calculate the mass in grams of zinc nitrate the chemist has added to the flask. Round your answer to significant digits.
Answer:
5.37g
Explanation:
0.21M means ; 0.21mol/dm³
1dm³=1L , so we can say 0.21mol/L
if 0.21mol of Zinc nitrate is contained in 1L of water
x will be contained in 135mL of water
x= 0.21*135*10³/1
=0.02835moles
number of moles= mass/ molar mass
mass= number of moles *molar mas
molar mass of Zn(NO₃)₂=189.36 g/mol
mass= 0.02835 *189.36
mass=5.37g
Answer:
D. Sweat evaporates from your skin
Explanation:
A physical change is a reversible process, no new substance is formed. A physical change does not affect the chemical composition of a substance.
Sweat evaporation from the skin is a physical change, because the change that occur is merely a change of state, Liquid to Gaseous state, no new substance is formed.
