Answer:
The answer to your question is Q = 18702.5 J
Explanation:
Data
mass of water = m = 447 g
Cp = 4.184 J/g°C
Temperature 1 = T1 = 25°C
Temperature 2 = T2 = 35°C
Heat = Q = ? Joules
Process
1.- Write the formula to calculate heat
Q = mCp(T2 - T1)
2.- Substitution
Q = (447)(4.184)(35 - 25)
3.- Simplification
Q = (447)(4.184)(10)
4.- Result
Q = 18702.5 J
Answer:
B
Explanation:
Heating a piece of iron until it glows.
Answer:
A. there is an isotope of lanthanum with an atomic mass of 138.9
Explanation:
By knowing the different atomic masses of both Lanthanum atoms, we can not tell anything about their occurence in nature. Therefore, all the last three options are incorrect. Because, the atomic mass does not tell anything about the availability or natural abundance of an element.
Now, the isotopes of an element are those elements, which have same number of electrons and protons as the original element, but different number of neutrons. Therefore, they have same atomic number but, different atomic weight or atomic masses.
Hence, by looking at an elements having same atomic number, but different atomic masses, we can identify them as isotopes.
Thus, the correct option is:
<u>A. there is an isotope of lanthanum with an atomic mass of 138.9.</u>
Answer:
The volume of the balloon will be 5.11L
Explanation:
An excersise to solve with the Ideal Gases Law
First of all, let's convert the pressure in mmHg to atm
1 atm = 760 mmHg
760 mmHg ___ 1 atm
755.4 mmHg ____ (755.4 / 760) = 0.993 atm
922.3 mmHg ____ ( 922.3 / 760) = 1.214 atm
T° in K = 273 + °C
28.5 °C +273 = 301.5K
26.35°C + 273= 299.35K
P . V = n . R .T
First situation: 0.993atm . 6.25L = n . 0.082 . 301.5K
(0.993atm . 6.25L) / 0.082 . 301.5 = n
0.251 moles = n
Second situation:
1.214 atm . V = 0.251 moles . 0.082 . 301.5K
V = (0.251 moles . 0.082 . 301.5K) / 1.214 atm
V = 5.11L
