Answer:
0.007 M
Explanation:
pH is defined as the negative logarithm of the concentration of hydrogen ions.
Thus,
pH = - log [H⁺]
The expression of the pH of the calculation of weak acid is:-
Where, C is the concentration = ?
Given, pH = 3.45
So, for 
, 
C = 0.007 M
Answer:
(a): 2,300 kilograms
(b): 0.005 kilograms
(c): 2.3 × 10^-5 kilograms
(d): 155 kilograms
Explanation:
Formulas:
(a); divide the mass value by 1000
(b); divide the mass value by 1e+6
(c); divide the mass value by 1e+9
(d); multiply the mass value by 1000
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:
D) 2, 4, and 5
Explanation:
In order to fully comprehend the answer choices we must take a close look at the value of ΔH° = 31.05. The enthalpy change of the reaction is positive. A positive value of enthalpy of reaction implies that heat was absorbed in the course of the reaction.
If heat is absorbed in a reaction, that reaction is endothermic.
Since ∆Hreaction= ∆H products -∆H reactants, a positive value of ∆Hreaction implies that ∆Hproducts >∆Hreactants, hence the answer choice above.
