Answer:
46.73ºC
Explanation:
The sheets will change heat to achieve the thermal equilibrium, it means that they'll have the same final temperature (T). The heat (q) must be equal for both in magnitude, but with opposite directions.
The heat flows from the higher temperature for the lower, so it flows from the iron (Fe) to the gold (Au) sheet:
qAu = -qFe
The heat can be calculated by the equation:
q = m*cp*ΔT
Where m is the mass, cp is the specif heat capacity, and ΔT the temperature variation.
CpAu = 0.129 J/gºC
CpFe = 0.444 J/gºC
10.2*0.129*(T - 19.4) = -19.9*0.444*(T - 50.8)
1.3158*(T - 19.4) = -8.8356*(T - 50.8)
1.3158T - 25.52652 = -8.8356T + 448.84848
1.3158T + 8.8356T = 448.84848 + 25.52652
10.1514T = 474.375
T = 46.73ºC
Answer: 10 ml of 200 mM is required and 30 ml of water is required.
Explanation:
According to the dilution law,
where,
= concentration of stock solution = 200mM
= volume of stock solution = ?
= concentration of resulting solution= 50mM
= volume of another acid solution= 40 ml
Thus 10 ml of 200 mM is required and (40-10) ml = 30 ml of water is to be added to make 40 ml of 50mM .
Answer:
C.) They have fewer electrons than protons
Explanation:
Charges on ions are determined by the ratio of electrons to protons. Neutral elements have the same number of protons and electrons. Remember: protons have a positive charge and electrons have a negative charge. However, based on the amount of electrons these elements have, some are more or less willing to give up their electrons to participate in ionic bonding. Potassium usually gives up 1 electron because this satisfies the octet rule. By removing this electron, the element has more protons than electrons, giving it an overall +1 charge.