Answer:
c = 0.898 J/g.°C
Explanation:
1) Given data:
Mass of water = 23.0 g
Initial temperature = 25.4°C
Final temperature = 42.8° C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.18 J/g°C
ΔT = 42.8°C - 25.4°C
ΔT = 17.4°C
Q = 23.0 g × × 4.18 J/g°C × 17.4°C
Q = 1672.84 j
2) Given data:
Mass of metal = 120.7 g
Initial temperature = 90.5°C
Final temperature = 25.7 ° C
Heat released = 7020 J
Specific heat capacity of metal = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.7°C - 90.5°C
ΔT = -64.8°C
7020 J = 120.7 g × c × -64.8°C
7020 J = -7821.36 g.°C × c
c = 7020 J / -7821.36 g.°C
c = 0.898 J/g.°C
Negative sign shows heat is released.
Answer : The moles of 
are, 2.125 mole.
Explanation : Given,
Molarity of = 8.500 M
Volume of solution = 250 mL = 0.250 L (1 L = 1000 mL)
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :
Now put all the given values in this formula, we get:
Therefore, the moles of are, 2.125 mole.
Answer:
Corrosion is the process of deterioration of materials as a result of chemical, electrochemical or other reactions. Rusting is a part of corrosion and is a chemical process which results in the formation of red or orange coating on the surface of metals. ... Rust or rusting can affect only iron and its alloys.
Explanation:
Answer:
The correct choice is E (47 neutrons, 35 protons, 36 electrons)
Explanation:
A ion of net charge -1 means that the ion wins an e-.
We dismiss options B and C.
We also dismiss option A because neutrons + protons = 81.
neutrons + protons = mass number
So we have E and C.
We see that C has 47 neutrons, 36 protons and 36 electrons and, as the atomic number matches the number of protons, we find out on the Periodic Table that the atomic number 36 represents to Krypton, a noble gas. It is impossible! A noble gas never can't be a ion of net charge.
Option E is correct, It is an isotope of Br.
Br has 35 protons (its atomic number)
47 neutrons, that's why it is an Isotope (Br has always 45 neutrons)
As usual, Br has 35 electrons, if it represents a ion of net charge -1, it menas it won 1 e-.
See the image below.
An excited electron is in a <em>high-energy state</em>.
When it drops to the lower-level ground state, it must get rid of this excess energy by <em>emitting it</em> as a quantum of light.
