Explanation:
Silver and Gold belong to a special group of metals known as the native metals. They are found naturally on their own and not in combined form in rocks.
- These metals are found uncombined because they are unreactive.
- They prefer to alloy with themselves.
- Calcium and magnesium on the other hand are reactive metals.
- The unreactivity of these metals makes them uncombined in nature.
Manipulation of the independent variable should change the dependent variable, the value of which "depends" on the independent variable's change in value.
Answer:
Energy sources do not have 100% efficiency because <em>the processes of energy conversion to usable forms involves energy losses. </em>
Some have lower efficiencies due to; <u>energy losses in form of heat</u> during conversion, <u>poor technology applied during conversion</u> of energy and<u> lack of desire equipment</u> to use in the energy conversion system.
Explanation:
The desired form of energy for use is derived from conversion of energy from the source using an energy converter into another form which is usable. The efficiency of the energy converter is calculated as;
л = output energy/input energy
The efficiency of energy is limited to the cost of equipment required for conversion from energy source by the energy converter to a form which is usable. Additionally, because energy sources are scarce, the technology to use in energy conversion is a factor affecting energy efficiency in that high efficiency will require advanced technology with better equipment leading higher costs of that energy form. when heat losses are involved during energy conversion, efficiency lowers, thus its better if such losses are used as energy input in another system.
Answer:
336.6 grams of CO₂ and 183.6 grams of H₂O are formed from 2.55 moles of propane.
Explanation:
In this case, the balanced reaction is:
C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of reactant and product participate in the reaction:
- C₃H₈: 1 mole
- O₂: 5 moles
- CO₂: 3 moles
- H₂O: 4 moles
Being the molar mass of each compound:
- C₃H₈: 44 g/mole
- O₂: 16 g/mole
- CO₂: 44 g/mole
- H₂O: 18 g/mole
Then, by stoichiometry, the following quantities of mass participate in the reaction:
- C₃H₈: 1 mole* 44 g/mole= 44 grams
- O₂: 5 moles* 16 g/mole= 80 grams
- CO₂: 3 moles* 44 g/mole= 132 grams
- H₂O: 4 moles* 18 g/mole= 72 grams
So you can apply the following rules of three:
- If by stoichiometry 1 mole of C₃H₈ forms 132 grams of CO₂, 2.55 moles of C₃H₈ how much mass of CO₂ will it form?
mass of CO₂= 336.6 grams
- If by stoichiometry 1 mole of C₃H₈ forms 72 grams of H₂O, 2.55 moles of C₃H₈ how much mass of H₂O will it form?
mass of H₂O= 183.6 grams
<u><em>336.6 grams of CO₂ and 183.6 grams of H₂O are formed from 2.55 moles of propane.</em></u>
The answer is; D
Enthalpy is the system’s internal energy ( considering the product of its pressure and volume). When the enthalpy is negative, it means that the products have a lower energy level than the reactants - meaning the system has dispensed some energy into the environment.
