class xii – preparatory examination - 1
... Questions number 28 to 30 are long answer questions and carry 5 marks each. vii) Use Log Tables,if necessary.Use of calculators is not allowed. ...
... Questions number 28 to 30 are long answer questions and carry 5 marks each. vii) Use Log Tables,if necessary.Use of calculators is not allowed. ...
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... 2007 by the combustion of 3.5 x 1015 g gasolne • Assuming that gasoline is octane, C8H18, the equation for the reaction is ...
... 2007 by the combustion of 3.5 x 1015 g gasolne • Assuming that gasoline is octane, C8H18, the equation for the reaction is ...
Periodic table Periodic Trends
... Amphoteric and amphiprotic oxides The terms amphoteric and amphiprotic are often mixed up. Amphoteric - a species that behaves as both an acid and a base i.e. Aluminum oxide Amphiprotic - a specific type of amphoteric species. These species are either proton (H+) donors or proton acceptors. i.e. sel ...
... Amphoteric and amphiprotic oxides The terms amphoteric and amphiprotic are often mixed up. Amphoteric - a species that behaves as both an acid and a base i.e. Aluminum oxide Amphiprotic - a specific type of amphoteric species. These species are either proton (H+) donors or proton acceptors. i.e. sel ...
elements of chemistry unit
... One type of chemical reaction involves the transfer of electrons from one species (species means atoms or groups of atoms) to another. REDOX REACTIONS These reactions are called oxidation reduction reactions. REDOX REACTIONS The species that loses electrons is oxidized and the species gaining electr ...
... One type of chemical reaction involves the transfer of electrons from one species (species means atoms or groups of atoms) to another. REDOX REACTIONS These reactions are called oxidation reduction reactions. REDOX REACTIONS The species that loses electrons is oxidized and the species gaining electr ...
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... the observed K1/2 values equal the dissociation constants Kd (see also ref 37): The same K1/2 values were observed in concentration dependences in which the maximal rate constant for reaction varied by more than 10-fold, which was accomplished by a 2′-H substitution at position -1 and by varying the ...
... the observed K1/2 values equal the dissociation constants Kd (see also ref 37): The same K1/2 values were observed in concentration dependences in which the maximal rate constant for reaction varied by more than 10-fold, which was accomplished by a 2′-H substitution at position -1 and by varying the ...
BIOC203W1_Lecture Slides_Enzymes
... Capacity of regulation or control: Enzymes can regulate the reactions rates in many different ways at several levels while chemical catalyst can’t do the same job. Physiological system is AUTOMATICALLY ECONOMIC while chemical system is not. ...
... Capacity of regulation or control: Enzymes can regulate the reactions rates in many different ways at several levels while chemical catalyst can’t do the same job. Physiological system is AUTOMATICALLY ECONOMIC while chemical system is not. ...
1. What energy changes occur when chemical bonds are formed
... The reaction is spontaneous at low temperatures but becomes non-spontaneous at high temperatures. ...
... The reaction is spontaneous at low temperatures but becomes non-spontaneous at high temperatures. ...
Chemical Reactions and Solution Stoichiometry
... Notice that in a combination reaction, the number of reactants is greater than the number of products (Figure 4.1.2). In a typical decomposition reaction (Interactive Figure 4.1.3), the number of products is greater than the number of reactants. The reaction is essentially the reverse of a combinati ...
... Notice that in a combination reaction, the number of reactants is greater than the number of products (Figure 4.1.2). In a typical decomposition reaction (Interactive Figure 4.1.3), the number of products is greater than the number of reactants. The reaction is essentially the reverse of a combinati ...
Unit 12: Electrochemistry
... Topic: Balancing Net Ionic Reactions Objective: How do we focus on the total end (net) ionic charges? Balancing Net Ionic Reactions: I. When balancing net ionic reactions, as in any type of balancing, the numbers of a species MUST be equal on both sides of a reaction. II. For net ionic reactions, th ...
... Topic: Balancing Net Ionic Reactions Objective: How do we focus on the total end (net) ionic charges? Balancing Net Ionic Reactions: I. When balancing net ionic reactions, as in any type of balancing, the numbers of a species MUST be equal on both sides of a reaction. II. For net ionic reactions, th ...
CHEMICAL EQUILIBRIUM
... 9. Each set of equilibrium concentrations is called an ______________________________. 10. There is only __________ equilibrium constant for a particular system at a particular temperature, but there are an ____________________ number of equilibrium positions. 11. The specific equilibrium position a ...
... 9. Each set of equilibrium concentrations is called an ______________________________. 10. There is only __________ equilibrium constant for a particular system at a particular temperature, but there are an ____________________ number of equilibrium positions. 11. The specific equilibrium position a ...
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes may occur.The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions often consist of a sequence of individual sub-steps, the so-called elementary reactions, and the information on the precise course of action is part of the reaction mechanism. Chemical reactions are described with chemical equations, which symbolically present the starting materials, end products, and sometimes intermediate products and reaction conditions.Chemical reactions happen at a characteristic reaction rate at a given temperature and chemical concentration. Typically, reaction rates increase with increasing temperature because there is more thermal energy available to reach the activation energy necessary for breaking bonds between atoms.Reactions may proceed in the forward or reverse direction until they go to completion or reach equilibrium. Reactions that proceed in the forward direction to approach equilibrium are often described as spontaneous, requiring no input of free energy to go forward. Non-spontaneous reactions require input of free energy to go forward (examples include charging a battery by applying an external electrical power source, or photosynthesis driven by absorption of electromagnetic radiation in the form of sunlight).Different chemical reactions are used in combinations during chemical synthesis in order to obtain a desired product. In biochemistry, a consecutive series of chemical reactions (where the product of one reaction is the reactant of the next reaction) form metabolic pathways. These reactions are often catalyzed by protein enzymes. Enzymes increase the rates of biochemical reactions, so that metabolic syntheses and decompositions impossible under ordinary conditions can occur at the temperatures and concentrations present within a cell.The general concept of a chemical reaction has been extended to reactions between entities smaller than atoms, including nuclear reactions, radioactive decays, and reactions between elementary particles as described by quantum field theory.