Equation mole ratio from

To find out the mass of a product that can be formed from a known mass of a reactant, we first convert the grams of reactant into moles, use the mole ratio from the balanced equation, and then convert the moles of product formed into grams. Essentially, we go through three steps ... 

In this approach, we use the mole ratio from the chemical equation to determine whether there is enough of one reactant to react with another. 

Convert the masses of the reactants and products to moles using their molar masses. Using the mole ratios from the balanced chemical equation, it is possible to determine how much material should react or be produced. These calculated values can be compared to the observed values. 

The strategy used for this and other redox titrations is outlined in Figure 4.5. As with acid-base titrations, the general idea is to measure a known amount of one substance—in this case, H2C204—and use mole ratios from the balanced equation to find the number of moles of the second substance—in this case, KMn04—necessary for complete reaction. With the molar amount of KMn04 thus... 

Calculate the mole ratios from the balanced equation. 

Step 5. Use the mole ratios from the balanced equation to fill in the remaining blanks. You can use the ratios because you know, from the balanced equation, that if 3.50 moles of HI are produced, one-half that amount of each reactant must have been used up (mass still has to be conserved) ... 

The correct answer is (B). This is a mole-to-mole conversion. If you have a balanced equation to start, you can solve these in your head. The mole ratios from the balanced equation allow you to quickly convert between moles of substances. The ratio of Cl2 to SiCl4 is 2 to 1. That means you will produce only half as many moles of SiCl4, or 1.92 mol. You can also solve the problem using a formula, as shown below ... 

The balanced chemical equation for this reaction shows that 1 mol of nitric acid reacts with 1 mol of sodium hydroxide. If equal molar quantities of nitric acid and sodium hydroxide are used, the result is a neutral (pH 7) aqueous solution of sodium nitrate. In fact, when any strong acid reacts with any strong base in the mole ratio from the balanced chemical equation, a neutral aqueous solution of a salt is formed. Reactions between acids and bases of different strengths usually do not result in neutral solutions. 

At the beginning of this chapter, you were introduced to Gay-Lussac s law of combining volumes When gases react, the volumes of the reactants and the products, measured at equal temperatures and pressures, are always in whole number ratios. As well, you learned that the mole ratios from a chemical equation are the same as the ratios of the volumes of the gases. 

From the equation, you know that 12.0 L of nitrogen gas is used. The mole ratios from the equation are... 

Step 2 Find the number of moles of iron present. Use this value, along with the mole ratios from the balanced equation, to find the number of moles of gas produced. 

Step 2 Calculate the number of moles of magnesium by dividing the mass given (m) by the molar mass of magnesium (M). Use the number of moles of magnesium, along with the mole ratio from the equation, to calculate the number of moles of hydrogen gas produced by the reaction. 

B 80 grams of Ca is equivalent to two moles of Ca. Two moles of Ca will react with two moles of Cl2 because the mole ratio from the balanced equation is 1 1. Two moles of Cl2 have a mass of 142 grams. This leaves 71 grams of the Cl2 gas in excess. 

Use the mole ratio from the balanced equation and substitute the new amount of reactants ... 

Use proportional reasoning to determine mole ratios from a balanced chemical equation. 

Substances are usually measured by mass or volume. As a result, before using the mole ratio you will often need to convert between the units for mass and volume and the unit mol Yet each stoichiometry problem has the step in which moles of one substance are converted into moles of a second substance using the mole ratio from the balanced chemical equation. Follow the steps in Skills Toolkit 2 to understand the process of solving stoichiometry problems. 

Although you could be given many different problems, the solution boils down to just three steps. Take whatever you are given, and find a way to change it into moles. Then, use a mole ratio from the balanced equation to get moles of the second substance. Finally, find a way to convert the moles into the units that you need for your final answer. 

You will write mole ratios from balanced chemical equations. 

Determine the moles of the unknown substance from the moles of the given substance. Use the appropriate mole ratio from the balanced chemical equation as the conversion factor. 

We can use the mole ratios from the balanced equation to determine the rates of change of other products and reactants. The rate of reaction can then be derived from any one of these individual rates. 

We express all concentrations in moles per liter. The mole ratio from the balanced chemical equation allows us to find the changes in concentrations of the other substances in the reaction. We use the reaction summary to find the equihbrium concentrations to use in the... 

To solve the problem, you need to know how the unknown moles of hydrogen are related to the known moles of potassium. In Section 11.1, you learned to derive mole ratios from the balanced chemical equation. Mole ratios are used as conversion factors to convert the known number of moles of one substance to the unknown number of moles of another substance in the same reaction. Several mole ratios can be written from the equation, but how do you choose the correct one ... 

You are given the moles of the reactant, CI2, and must determine the mass of the product, NaCI. You must convert from moles of CI2 to moles of NaCI using the mole ratio from the equation. Then, you need to convert moles of NaCI to grams of NaCI using the molar mass as the conversion factor. 

Starting with the amount of ammonia produced (6.0 moles), we can use the mole ratio from the balanced equation to calculate the moles of H2 and N2 that reacted to produce 6.0 moles of NH3. 

---