Answer:
Q = -1045 J
Explanation:
Given data:
Mass of water = 5.00 g
Initial temperature = 348.0 K
Final temperature = 298.0 K
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.K
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 = 298.0 K - 348.0 K
ΔT = - 50 K
Q = 5.0 g ×4.18 J/g.K× - 50 K
Q = -1045 J
Answer:
Question 7 the answer is B
Explanation:
In every nuclear reaction there is always formation of products either by nuclei bombardment or by the elements breaking into two elements of the same mass
Question 8
The answer is A
Nuclear reactions release a huge amount of energy than chemical reactions
Answer:
40.68 % C
23.73 % N
8.47% H
27.12% O
Explanation:
The mass percent of an element X in a compound is calculated as the molar mass (MM) of X multiplied by the number of atoms of X in the compound, divided into the molecular weight (MW) of the compound, as follows:
mass percent of X = (MM(X) x number of atoms of X)/MW compound x 100
Thus, we first calculate the MW of acetamide (C₂H₅NO) by using the molar mass of the chemical elements C, H, N and O:
MW(C₂H₅NO) = (12 g/mol C x 2) + (1 g/mol H x 5) + 14 g/mol N + 16 g/mol O = 59 g/mol
Now, we can calculate the mass percent of each element (C, H, N, O) in C₂H₅NO:
- Mass percent of C (2 atoms of C in 1 molecule of C₂H₅NO):
% mass C = (12 g/mol x 2)/(59 g/mol) x 100 = 40.68 %
- Mass percent of N (1 atom of N in 1 molecule of C₂H₅NO):
% mass N = (14 g/mol x 1)/(59 g/mol) x 100 = 23.73 %
- Mass percent of H (5 atoms of H in 1 molecule of C₂H₅NO):
% mass H = (1 g/mol x 5)/(59 g/mol) x 100 = 8.47 %
- Mass percent of O (1 atom of O in 1 molecule of C₂H₅NO):
% mass O = (16 g/mol x 1)/(59 g/mol) x 100 = 27.12 %
The sum of the mass percents has to be equal to 100%:
40.68 % C + 23.73 % N + 8.47% H + 27.12% O = 100%
Answer:
Explanation: A compound with the empirical formula SO has a molecular weight of 96.13