Hello!
The reaction that the graph represents is
A. Exothermic because Hrxn=-167 kJTo calculate Hrxn we apply the following equation:
Looking at the graph, and at the result of the calculations, we can see that the enthalpy of the products is
lower than the enthalpy of the reagents, because the sign is negative. That means that the reaction
releases energy in the form of heat and that the reaction is
exothermic.
Have a nice day!
Answer:
C.Melt both cubes and look for a broader range of melting temperatures. The one that melts over a broader range of temperatures is the amorphous solid.
Explanation:
Amorphous solids is one that do not have a fixed melting points but melt over a wide range of temperature due to the irregular shape hence its name. Contrariwise crystalline solids, have a fixed and sharp melting point.
This comes in handy to solve the riddle. We can characterise the pair with the melting point property.
Answer:
0.106 mol (3s.f.)
Explanation:
To find the number of moles, divide the mass of glucose (in grams) by its Mr. Glucose has a chemical formula of C6H12O6. To find the Mr, add all the Ar of all the atoms in C6H12O6.
Ar of C= 12, Ar of H= 1, Mr of O= 16
These Ar values can be found on the periodic table.
Mr of glucose= 6(12)+ 12(1) + 6(16)= 180
Moles of glucose
= mass ÷ mr
= 19.1 ÷ 180
= 0.106 mol (3 s.f.)
Answer:
c = 0.377 J/g.°C
c = 0.2350 J/g.°C
J = 27.3 J
Explanation:
We can calculate the heat (Q) absorbed or released by a substance using the following expression.
Q = c × m × ΔT
where,
c: specific heat
m: mass
ΔT: change in the temperature
<em>It takes 49.0J to raise the temperature of an 11.5g piece of unknown metal from 13.0°C to 24.3°C. What is the specific heat for the metal? Express your answer numerically, in J/g.°C</em>
Q = c × m × ΔT
49.0 J = c × 11.5 g × (24.3°C - 13.0°C)
c = 0.377 J/g.°C
<em>The molar heat capacity of silver is 25.35 J/mol.°C. How much energy would it take to raise the temperature of 11.5g of silver by 10.1°C? Express your answer numerically, in Joules. What is the specific heat of silver?</em>
<em />
The molar mass of silver is 107.87 g/mol. The specific heat of silver is:
Q = c × m × ΔT
Q = (0.2350 J/g.°C) × 11.5 g × 10.1°C = 27.3 J
When we go to periodic table, Sulfur is
an element that has 16 protons and 16 electrons.
when there is 18 electrons, with number of two electrons more than protons. This makes it an ion and
the ion has a -2 charge.
So when there is16 protons, 18 neutrons, and 18 electrons the symbol is S⁻².
The neutrons have no charge but they add only mass to the
elements. So when there is 16 neutrons, it doesn't change the symbol of ion.
