Answer:
DE2
Explanation: for every one D+2 you need two E-1 because +2=-2
Answer:
Check if the ions of two compounds exchange places.
Explanation:
The definition of single replacement is a reaction when an ion replaces another ion, thus the name.
Answer:
7.5 g
Explanation:
There is some info missing. I think this is the original question.
<em>Ammonium phosphate ((NH₄)₃PO₄) is an important ingredient in many fertilizers. It can be made by reacting phosphoric acid (H₃PO₄) with ammonia (NH₃). What mass of ammonium phosphate is produced by the reaction of 4.9 g of phosphoric acid? Be sure your answer has the correct number of significant digits.</em>
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Step 1: Write the balanced equation
H₃PO₄ + 3 NH₃ ⇒ (NH₄)₃PO₄
Step 2: Calculate the moles corresponding to 4.9 g of phosphoric acid
The molar mass of phosphoric acid is 98.00 g/mol.

Step 3: Calculate the moles of ammonium phosphate produced from 0.050 moles of phosphoric acid
The molar ratio of H₃PO₄ to (NH₄)₃PO₄ is 1:1. The moles of (NH₄)₃PO₄ produced are 1/1 × 0.050 mol = 0.050 mol.
Step 4: Calculate the mass corresponding to 0.050 moles of ammonium phosphate
The molar mass of ammonium phosphate is 149.09 g/mol.

Explanation:
4. limestone heat lime + carbon dioxide
The reactants in this expression above is limestone
The products of the reaction is carbon dioxide and lime
Reactant is the species that gives the product and it is usually found on the left hand side of the expression.
The product is the substance on the right hand side of the expression that forms through the experiment.
Heat is used to facilitate the reaction.
5. An exothermic reaction is a reaction in which heat is given off.
An endothermic reaction is a reaction in which heat is absorbed in the process.
An exothermic reaction is always warmer after the reaction whereas an endothermic reaction is colder at the end of the reaction.