Answer:
Mass of iron = 59.375 gm
Explanation:
Calories ( or joules) are added to the water by the hot steel so at the endpoint they are BOTH at 40 C
The water gains:
4.18 j/g-C * 50 * (40-30 C) = 2090 j
The steel gave up 2090 j going from 120 to 40 C
2090 = .44 j/g-C * m * (120-40) solve fro m = 59.375 gm
Answer: <span>
A hexagon with nothing drawn inside it does not represent Benzene.
Explanation:Below attached picture contains structures mentioned in given option.
Structure of
Option-A is shown in
Red Color.
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Structure of
Option-B is shown in
Blue Color.
Structure of
Option-C is shown in
Green Color.
Structure of
Option-D is shown in
Orange Color.
Result: Except Option-A, all structures represent Benzene. Option-A in fact shows the structure of Cyclohexane.
Answer:
B
Explanation:
Balanced equations have the same number of elements on both sides. If the number of elements are equal to each other for every element in the equation on both sides, then the equation is balanced.
Important concept : The big number before an element or compound represents how many molecules of that compound or element there are in a reaction. To find the number of atoms of each element you multiply the coefficient by the subscript ( small number ) which represents the number of atoms of that element in each molecule. Ex. 3H2O. There is a coefficient of 3 meaning that there are 3 molecules of H2O. There is a subscript after H meaning there are 2 atoms of hydrogen in each molecule. To find the total number of atoms we multiply the subscript of hydrogen by the coefficient of the whole molecule. 3 * 2 = 6 , so there are a total of 6 atoms of hydrogen in 3H2O
A) Cu + 2AgNO3 ==> CuNO3 + 2Ag
1 Cu 1
2 Ag 2
2 N 1
3 O 3
The amount of nitrogen atoms is different on both sides of the equation therefore this is not a balanced equation
B) CCl4 + O2 ==> CO2 + 2Cl2
1 C 1
4 Cl 4
2 O 2
The number of atoms of each element is the same on both sides of the equation therefore this is the balanced equation, however lets check the other answer choices just in case.
C) 2K + H2SO4 ==> K2SO4 + 2H2
2 K 2
1 H 4
1 S 1
4 O 4
The number of Hydrogen atoms are different on each side of the equation therefore this is not a balanced equation.
D) 2Al2O3 ==> 2Al + 3O2
4 Al 2
6 O 6
There are a different amount of aluminum atoms on both sides of the equation therefore this is not a balanced equation.
The atomic number for Pb is 82
∴ Pb has 82 protons and 206-82 = 14 protons
The actual mass of Pb nuclei is
=(82 × mass of the proton) + (124 × mass of neutron)
=(82× 1.00728) + (124 × 1.008664) amu
= 207.6713 amu
The mass of lead which is given is 205.9744 amu
∴mass defect is
m = 207.6713 - 205.9744 = 1.6969 amu
=1.6969 × 1.66054 × 10⁻²⁷kg
=2.818 × 10⁻²⁷kg
The binding energy is E = mc²
C is the speed of light in vacuum = 2.9979 × 10⁸m/s
∴ E = 2.532 × 10×⁻¹⁰ J/mol
= 2.532 × 10⁻¹⁰ × 6.023 × 10²³ J/mol
= 1.53811 × 10¹⁴ J/mol
