Rate of reaction increases when surface area increases.

The rate of a chemical reaction can be raised by increasing the surface area of a solid reactant. This is done by cutting the substance into small pieces, or by grinding it into a powder. If the surface area of a reactant is increased: the rate of reaction increases.

Increasing the surface area increases the rate of solubility of a solid because a larger number of molecules of the greater surface area have contact with the solvent.

Increasing surface area leads to an increased number of catalytic sites available for reaction, thereby increasing catalyst productivity.

Surface area does not affect how much of a solute will be dissolved, but it is a factor in how quickly or slowly the substance will dissolve.

If the surface area of a reactant is increased: more particles are exposed to the other reactant. there is a greater chance of particles colliding, which leads to more successful collisions per second. the rate of reaction increases.

There are four factors that affect the rate (speed) of a chemical reaction:

• temperature.
• concentration.
• particle size.
• use of a catalyst.

Five factors typically affecting the rates of chemical reactions will be explored in this section: the chemical nature of the reacting substances, the state of subdivision (one large lump versus many small particles) of the reactants, the temperature of the reactants, the concentration of the reactants, and the …

Grinding one of the reactants into a powder will usually cause a reaction to speed up.

Activation Energy is the minimum amount of energy needed to start a chemical reaction.

Activation energy, in chemistry, the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo chemical transformation or physical transport.

The change in enthalpy of a reaction depends solely on the chemical compositions of the reactants and products, not on the path taken to get from one to the other hence it will not affect activation energy and vice versa. Hence, the value of ΔH DOES NOT AFFECT the rate of reaction.

The sequence of individual steps, or elementary reactions, by which reactants are converted into products during the course of a reaction is called the reaction mechanism. The overall rate of a reaction is determined by the rate of the slowest step, called the rate-determining step.

An increase in temperature typically increases the rate of reaction. An increase in temperature will raise the average kinetic energy of the reactant molecules. Therefore, a greater proportion of molecules will have the minimum energy necessary for an effective collision (Figure.

k is the first-order rate constant, which has units of 1/s. The method of determining the order of a reaction is known as the method of initial rates. The overall order of a reaction is the sum of all the exponents of the concentration terms in the rate equation.

: a chemical reaction in which the rate of reaction is directly proportional to the concentration of the reacting substance — compare order of a reaction.

A rate law is an expression showing the relationship of the reaction rate to the concentrations of each reactant. The specific rate constant (k) is the proportionality constant relating the rate of the reaction to the concentrations of reactants. The value of the rate constant is temperature dependent.

: a chemical reaction in which the rate of reaction is proportional to the concentration of each of two reacting molecules — compare order of a reaction.

Reactions in which reactants are identical and form a product can also be second order reactions. Many reactions such as decomposition of nitrogen dioxide, alkaline hydrolysis of ethyl acetate, decomposition of hydrogen iodide, formation of double stranded DNA from two strands etc.

Second order reactions can be defined as chemical reactions wherein the sum of the exponents in the corresponding rate law of the chemical reaction is equal to two. The rate of such a reaction can be written either as r = k[A]2, or as r = k[A][B].

For a first-order reaction, a plot of the natural logarithm of the concentration of a reactant versus time is a straight line with a slope of −k. For a second-order reaction, a plot of the inverse of the concentration of a reactant versus time is a straight line with a slope of k.

0.0259 seconds

The overall order of the reaction is found by adding up the individual orders. For example, if the reaction is first order with respect to both A and B (a = 1 and b = 1), the overall order is 2.

To calculate percent slope, divide the difference between the elevations of two points by the distance between them, then multiply the quotient by 100. The difference in elevation between points is called the rise. The distance between the points is called the run. Thus, percent slope equals (rise / run) x 100.

Table of Common Slopes in Architecture

A positive slope means that two variables are positively related—that is, when x increases, so does y, and when x decreases, y decreases also. Graphically, a positive slope means that as a line on the line graph moves from left to right, the line rises.

If you “rise up”, the number is positive; if you “rise down”, the number is negative. Now, you ALWAYS “run over”! If you follow the procedure correctly, you will always run over to the right.

A way to remember this is to think about the numbers are on the x-axis. Going to the right of the origin are the positive values, and going to the left of the origin are the negative values. If the slope is positive, then the rise and the run need to either be BOTH positive or BOTH negative.

The rise over run formula is referred to as the slope formula where the fraction consists of a rise whether the line is going up or down divided by the run i.e. either the line is going left or right.

When calculating the rise of a line’s slope, down is always negative and up is always positive. When calculating the run of a line’s slope, right is always positive and left is always negative.