Answer:
3.91x10²³ atoms of lead
Explanation:
In chemistry, a mole of a substance is defined as 6.022x10²³ particles that could be atoms, molecules, ions, etc.
As you can see, in the problem, you have 0.650moles of lead in a fishing line sinker, the present atoms are:
=<em> 3.91x10²³ atoms of lead</em>
Answer:
d. none of the above (all have the same kinetic energy)
Explanation:
The kinetic theory of gases states that the molecules of an ideal gas experience a constant random motion.
At standard temperature and pressure (STP), the kinetic energy of an ideal gas such as hydrogen, argon, neon, sodium, oxygen, helium, magnesium, beryllium, nitrogen, carbon, fluorine, chlorine etc are all the same.
The standard temperature and pressure (STP) of an ideal gas is 273K and 100 kPa.
Hence, all of the gases have the same kinetic energy at standard temperature and pressure (STP).
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
Where, K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
Answer:
21.21°C will be the final temperature of the solution in a coffee cup calorimeter.
Explanation:
= enthalpy change = -57.2 kJ/mol of NaOH
Moles of sodium hydroxide = n
Molarity of the NaOH = 0.250 M
Volume of NaOH solution = V = 50.00 mL = 0.050 L
Moles of HCl = n'
Molarity of the HCl= 0.250 M
Volume of HCl solution = V' = 50.00 mL = 0.050 L
Since 1 mole of Hcl reacts with 1 mole of NaoH. Then 0.0125 mole of HCl will react with 0.0125 mole of NaOH.
The enthalpy change during the reaction.
q = heat released on reaction= -715 J
now, we calculate the heat gained by the solution.:
Q= -q = -(-715 J) = 715 J
m = mass of the solution = ?
Volume of the solution formed by mixing, v = 50.00 ml + 50.00 mL = 100.00 mL
Density of the solution = density of water = d = 1 g/mL
m = 100 g
q = heat gained = ?
c = specific heat =
= final temperature = ?
= initial temperature =
Now put all the given values in the above formula, we get:
21.21°C will be the final temperature of the solution in a coffee cup calorimeter.