Answer:
1. 0.0154mole of PbS
2. Double displacement reaction
Explanation:
First, let write a balanced equation for the reaction. This is illustrated below:
Pb(CH3COO)2 + H2S —> PbS + 2 CH3COOH
Molar Mass of Pb(CH3COO)2 = 207 + 2(12 + 3 + 12 + 16 +16) = 207 + 2(59) = 207 + 118 = 325g
Mass of Pb(CH3COO)2 = 5g
Number of mole = Mass /Molar Mass
Number of mole of Pb(CH3COO)2 = 5/325 = 0.0154mole
From the equation,
1mole of Pb(CH3COO)2 produced 1mole of PbS.
Therefore, 0.0154mole of Pb(CH3COO)2 will also produce 0.0154mole of PbS
2. The name of the reaction is double displacement reaction since the ions in the two reactants interchange to form two different products
Answer:
The Spaniards practically went to war with the native Americans in South America, such as the Inca. They also brought diseases to South America. Diseases like smallpox.
Explanation:
Then after effectively killing off most of the native American population the Spanish continued to use South America for resources and they enslaved most of what was left of the non-Spanish and mixed populations. Francisco Pizarro took a page from Cortes' book, capturing Atahualpa, Emperor of the Inca, in 1532 and Cortes was the conquistador who defeated the Aztec Empire in what is now modern day Mexico or Central America.
Answer:
cutting, bending, dissolving, freezing, and boiling
Explanation:
A physical change is a change in one or more physical properties of matter without any change in chemical properties. In other words, matter doesn't change into a different substance in a physical change. Examples of physical change include but are not limited to, from solid to liquid or from liquid to gas are also physical changes.
The answer is 64.907 amu.
The atomic mass of an element is the average of the atomic masses of its isotopes. The relative abundance of isotopes must be taken into consideration, therefore:
atomic mass of copper = atomic mass of isotope 1 * abundance 1 + atomic mass of isotope 2 * abundance 2
We know:
atomic mass of copper = 63.546 amu
The atomic mass of isotope 1 is: 62.939 amu
The abundance of isotope 1 is: 69.17% = 0.6917
The atomic mass of isotope 1 is: x
The abundance of isotope 2: 100% - 69.17% = 30.83% = 0.3083
Thus:
63.546 amu = 62.939 amu * 0.6917 + x * 0.3083
63.546 <span>amu = 43.535 amu + 0.3083x
</span>⇒ 63.546 amu - 43.535 amu = 0.3083x
⇒ 20.011 amu = 0.3083x
⇒ x = 20.011 amu ÷ 0.3083 = 64.907 amu
Answer:
Explanation:
Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.
With Hess's Law in mind, let's see how A can be converted to 2C +E.
(Δ
) -----(1)
Since we have 2B, multiply the whole of II. by 2:
(2Δ
) -----(2)
This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is 
.
Reversing III. gives us a negative enthalpy change as such:
(-Δ
) -----(3)
This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of 
, which is also the equation of interest.
Adding all three together:
(
)
Thus, the first option is the correct answer.
Supplementary:
To learn more about Hess's Law, do check out: brainly.com/question/26491956
