Answer:
Avogadro number of pennies will extend to a distance of 6.02 * 10¹⁷ km
<em>Note: The question is missing some parts. The complete question is as follows;</em>
<em>A penny has a thickness of approximately 1.0 mm . If you stack ed Avogadro's number of pennies one on top of the other on Earth 's surface, how far would the stack extend (in km)? [For comparison, the sun is about 150 million km from Earth and the nearest star (Proxim a Centauri) is about 40 trillion km from Earth.]</em>
Explanation:
Avogadro number = 6.02 * 10²³
thickness of a penny = 1.0 mm
I mm = 0.001 m
Thickness of Avogadro number of pennies stacked one upon another will be:
6.02 * 10²³ * 0.001 m = 6.02 * 10²⁰ m
Distance in km;
1 m = 0.001 km
therefore, 6.02 * 10²⁰ m = 6.02 * 10²⁰ * 0.001 km = 6.02 * 10¹⁷ km
Avogadro number of pennies will extend to a distance of 6.02 * 10¹⁷ km
Answer:
Rate constant = 0.0237 M-1 s-1, Order = Second order
Explanation:
In this problem, it can be observed that as the concentration decreases, the half life increases. This means the concentration of the reactant is inversely proportional to the half life.
The order of reaction that exhibit this relationship is the second order of reaction.
In the second order of reaction, the relationship between rate constant and half life is given as;
t1/2 = 1 / k[A]o
Where;
k = rate constant
[A]o = Initial concentration
k = 1 / t1/2 [A]
Uisng the following values;
k = ?
t1/2 = 113
[A]o = 0.372M
k = 1 / (113)(0.372)
k = 1 / 42.036 = 0.0237 M-1 s-1
Answer:
Pure copper sulphate can be obtained from an impure sample by re-crystallization. The impure sample is dissolved in water, heated and then cooled which then later forms crystals. These copper sulphate crystals are then separated by filtration and drying.
Answer:
Polar covalent bond
Explanation:
On the basis of electronegativity bond could be ionic bond, polar and non pole covalent bond.
Ionic bond:
It is the bond which is formed by the transfer of electron from one atom to the atom of another element.
Both bonded atoms have very large electronegativity difference. The atom with large electronegativity value accept the electron from other with smaller value of electronegativity. The electronegativity difference between bonded atoms is greater than 1.7.
For example:
Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion. Both atoms are bonded together electrostatic attraction occur between anion and cations.
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive. There are two type of covalent bond. Polar and non polar covalent bond. When electronegativity difference is 0.4 - 1.7 bond is polar covalent bond when it is less than 0.4 the bond is non polar covalent.
For example:
In CO the electronegativity of oxygen is 3.5 and carbon is 2.5. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and carbon becomes partial positive. and bond is polar covalent.
