Diborane: Properties, Reactions, and Structure
Diborane is a chemical compound that consists of boron and hydrogen atoms, and has a molecular formula B²H⁶. This substance is highly unstable at room temperature. The compounds consisting of boron and hydrogen atoms are called boranes. Diborane is one of the simplest borane hydrides.
Methods of Preparation:
- When boron trifluoride is treated with Li or sodium hydride in ethereal solution, B2H6 is formed. 2BF3 + 6LiH – ether – 6LiF + B2H6. 2BF3 + 6NaOH – ether – 6NaOH + B2H6.
- B2H6 is obtained from
Properties of Copper Alloys, Nickel, Magnesium, Aluminum, and Annealing
Copper Alloys
Copper alloys: Great ductility without allowing thanks to that can be easily cold worked and matching not so easy. Corrosion resistance is outstanding in most normal environment. Mechanical properties are quite limited and they can improved with alloying materials. Most copper alloys cannot be hardened or strengthened by heat-treating procedures, cold working or solid solution to improve mechanical properties. Brass: copper + zinc. Alpha phase stable up to 35%. FCC crystal structure
Read MoreEvolution and Adaptation in Science
History of Science
As an example of the changes in ideas of this time, we will examine the behavior of a simple pendulum. Until the 16th century, Aristotle’s theory of pendulums held that the period (the length of time for one swing back and forth), depended on the amplitude (the distance the pendulum swung). We shall now test this idea, just as Galileo did.
A pendulum is a weight hanging from a fixed point by a string or wire which, when pulled back and released, is free to swing in and down due
Read MoreChemical Reaction Rates and Molar Concepts
Reaction Rate
Of a chemical reaction is defined in terms of the time it takes to make a reactant disappear or for a product to appear.
Collinson Theory
Chemical reactions break and form bonds as a result of collision between elemental units of the reactants. Not all cause the breaking or forming of bonds, not all collision are effective. Only collision with sufficient energy and whose molecules have the right orientation may break or form bonds.
Factors That Affect Reaction Rates
- Temperature: In reactions
Molar Mass of Solute and Sulfuric Acid Manufacturing Process
An aqueous solution of 2% non-volatile solute exerts a pressure of 1.004 bar at the normal boiling point of the solvent. What is the molar mass of the solute?
Here,
Vapour pressure of the solution at normal boiling point (p1) = 1.004 bar (Given)
Vapour pressure of pure water at normal boiling point (p10) = 1.013 bar
Mass of solute, (w2) = 2 g
Mass of solvent (water), (w1) = 100 – 2 = 98 g
Molar mass of solvent (water), (M1) = 18 g mol – 1
According to Raoult’s law,
(p10 – p1) / p10 =
Designing a New Sand Filter for a Small Operation: Sizing, Media, and Filtration Methods
The estimated flow rate for this site is 2000 m3/day. The surface overflow rate should exceed 125 m3/m2/d. What will be the surface area of the filter? You can use some leftover Ottawa sand (d10 = 0.00055m) from your last filtration project. How deep should the filter be?
Let’s make the filter 4 m x 4m.
Depth (L) should be: 1000
So, let L = 1 m; gives us: L/d10 = 1m/0.00055m = 1818 so choose 1m depth.
* Removal Efficiency = 1 – 0.29 = 0.71 = 71%
Determine the matching sizes (d10) of anthracite (
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