Pure metals possess few important physical and metallic properties, such as melting point, boiling point, density, specific gravity, high malleability, ductility, and heat and electrical conductivity. These properties can be modified and enhanced by alloying it with some other metal or nonmetal, according to the need.
Alloys are made to:
Enhance the hardness of a metal: An alloy is harder than its components. Pure metals are generally soft. The hardness of a metal can be enhanced by alloying it with another metal or nonmetal.
Lower the melting point: Pure metals have a high melting point. The melting point lowers when pure metals are alloyed with other metals or nonmetals. This makes the metals easily fusible. This property is utilized to make useful alloys called solders.
Enhance tensile strength: Alloy formation increases the tensile strength of the parent metal.
Enhance corrosion resistance: Alloys are more resistant to corrosion than pure metals. Metals in pure form are chemically reactive and can be easily corroded by the surrounding atmospheric gases and moisture. Alloying a metal increases the inertness of the metal, which, in turn, increases corrosion resistance.
Modify color: The color of pure metal can be modified by alloying it with other metals or nonmetals containing suitable color pigments.
Provide better castability: One of the most essential requirements of getting good castings is the expansion of the metal on solidification. Pure molten metals undergo contraction on solidification. Metals need to be alloyed to obtain good castings because alloys
Answer is: pH value of morphine is 10.64.<span>
Chemical reaction: </span>C₁₇H₁₉NO₃ + H₂O → C₁₇H₁₉NO₃H⁺ +OH⁻.<span>
Kb(</span>C₁₇H₁₉NO₃) = 10∧(-5,79) = 1,62·10⁻⁶.<span>
c(</span>C₁₇H₁₉NO₃<span>) = 0,115 M.</span><span>
Kb(</span>C₁₇H₁₉NO₃) = c(OH⁻) · c(C₁₇H₁₉NO₃H⁺) ÷ c(C₁₇H₁₉NO₃).<span>
c(OH</span>⁻)
= c(C₁₇H₁₉NO₃H⁺) = x.
1,62·10⁻⁶<span> = x² ÷
(0,115 - x).</span><span>
Solve quadratic equation: x = c(OH</span><span>⁻) = </span><span>0,000431 M.
pOH = -log(</span>0,000431 M<span>) = 3,36.
pH = 14 - 3,36 = 10,64.</span>
Answer:
The answer to your question is below
Explanation:
Propane = C₃H₈
Process
1.- Write the chemical reaction
C₃H₈ + O₂ ⇒ CO₂ + H₂O
balanced chemical reaction
C₃H₈ + 5O₂ ⇒ 3CO₂ + 4H₂O
Reactants Elements Products
3 C 3
8 H 8
10 O 10
b) Standard enthalpy
Propane -104.7 kJ/mol
Oxygen 0 kJ/mol
Carbon dioxide -393.5 kJ/mol
Water -241.8 kJ/mol
ΔH° = ∑ΔH° products - ∑H° reactants
ΔH° = 3(-393.5) + 4(-241.8) - [(-104.7) + 0]
-Simplification
ΔH° = -1180.5 kJ/mol - 967.2 kJ/mol + 104.7 kJ/mol
ΔH° = - 2042.5 kJ/mol
This reaction is exothermic because ΔH° is negative.
Answer:
6 moles of oxygen are needed to make 12 moles of magnesium oxide.
Explanation:
First of all you should know that the balanced chemical equation is:
2 Mg + O₂ → 2 MgO
The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) , the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:
a ⇒ b
c ⇒ x
So:
In this case the rule of three applies as follows: if 2 moles of magnesium oxide are produced from 1 mole of oxygen, 12 moles of magnesium oxide from how many moles of oxygen is produced?
moles of oxygen= 6
<u><em>6 moles of oxygen are needed to make 12 moles of magnesium oxide.</em></u>
Answer:
reactants: 2 O2
products: 3 CO2, 4 NO2, 6 H2O
Explanation:
In a combustion, a combustible material, which generally is composed of C, H, O, N, and S, is combusted, that is, react with oxygen after a spark was produced; obtaining fire, heat and subproducts, including ashes and gases.
Oxygen is always one of the reactants of a combustion.
If Nitrogen was present in the combustible, NO2 (or other nitrogen oxides) will be produced.
If Carbon was present in the combustible, CO2 will be produced (also CO can be produced).
If Hydrogen was present in the combustible, H2O will be produced.
