You'll want to add three amounts of heat.
(1) Specific heat of lowering the temperature from -135°C to the melting point -114°C
(2) Latent heat of fusion/melting
(3) Specific heat of elevating the temperature from -114°C to -50°C
(1) E = mCΔT = (25 g)(0.97 J/g·°C)(1 kJ/1000 J)(-114 - -135) = 0.509 kJ
(2) E = mΔH = (25 g)(5.02 kJ/mol)(1 mol/46.07 g ethanol) = 2.724 kJ
(3) E = mCΔT = (25 g)(2.3 J/g·°C)(1 kJ/1000 J)(-50 - -114) = 3.68 kJ
<em>Summing up all energies, the answer is 6.913 kJ.</em>
Answer:
The electron configuration for this atom is Calcium, which has 2 valence electrons.
Explanation:
Following the periodic table and with the electron configuration, you will end up with calcium, which has 2 valence electrons. (Always follow the electron configuration from left to right! It begins at hydrogen, then to helium... and so on.)
1s2 -> He....
2s2 -> Be....
2p6 -> Ne...
3s2 -> Mg...
3p6 -> Ar...
4s2 -> Ca.
The form of heat transfer taking place in the crust of the Earth would be Convection.
The balanced chemical reaction would be
<span>fecl2 + 2naoh = fe(oh)2(s) + 2nacl
Initial amounts of the reactants are given, so, we need to determine which of the reactants is the limiting reactant and use this amount to determine what is asked. However, what is being asked is how many of the FeCl2 is used in the reaction, showing that it is NaOH that is the limiting reactants. Thus, we just use the initial amount of NaOH and relate the substances by the chemical reaction as follows:
6 mol NaOH ( 1 mol FeCl2 / 2 mol NaOH ) = 3 mol FeCl2
Therefore, 3 moles of FeCl2 is used up and 3 moles of FeCl2 is also left after the reaction.</span>
Answer:
6 grains
Explanation:
The equation of the reaction between NaOH and aspirin is;
C9H8O4(aq) + NaOH (aq) ------>C9H7O4Na(aq) + H2O(l)
Amount of NaOH reacted = concentration × volume = 0.1466 M × 14.40/1000 L = 2.11 × 10^-3 moles
Given that aspirin and NaOH react in a mole ratio of 1:1 from the balanced reaction equation above, the number of moles of aspirin reacted is 2.11 × 10^-3 moles
Hence mass of aspirin reacted = 2.11 × 10^-3 moles × 180.2 g/mol = 0.38 g
If 1 grain = 0.0648 g
x grains = 0.38 g
x= 0.38 g/0.0648 g
x= 6 grains
