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Name _________KEY______ Balanced Equations, Chemical Bonding & Reactions Test Review (Chapters 13 & 14) 1. Most reactions in your body are sped up by enzymes which are referred to chemically as ___catalysts_____. In order to slow down a reaction, a chemist would use a(n) _____inhibitor__. 2. We balance equations to justify the ___Law of Conservation of Matter/Mass______, because matter cannot be created or destroyed. 3. Balance the following equations. Use an inventory sheet to solve. a. 2Na3PO4 + 3Ca(NO3)2 → 6NaNO3 + Ca3(PO4)2 (hint: one coefficient is a 6!) b. 3Mg + Mn2O3 → 3MgO + 2Mn 4. Identify by name and count how many atoms of each element are in the formula 2 Mg(C2H3O2)2. ____ 2 magnesium, 8 carbon, 12 Hydrogen, and 8 oxygen_____ 5. An ionic bond is between a __metal__ and a ___nonmetal___. 6. Write the formula for the molecule phosphorus trichloride. ____PCl3____ 7. What are four clues that a chemical reaction is taking place? a. ___bubbling / gas production ________ e. breaking apart b. ____color change_____________ f. combustion c. ____energy change – exothermic & endothermic______ d. ____formation of a solid / precipitate____ 8. Identify by name the reactants and products in the equation Na2O + H2O → 2 NaOH. ___reactants – sodium oxide and water and product – sodium hydroxide______ 9. True / False When balancing chemical equations, you can either add a coefficient or change a formula in the equation. 10. What is the total charge of this compound? (NH4)2CO3 __neutral! Or 0______ 11. Light energy is released in the ___exothermic____ reaction of Chem-Lights (light sticks), whereas energy is taken in during the ____endothermic____ reaction of a chemical ice pack. 12. Use your oxidation chart to write the formulas for the following polyatomic ions: a. aluminum phosphate ____AlPO4________ b. hydrogen peroxide __H2O2____ c. aluminum sulfate ____Al2(SO4)3____ 13. Write the name for the formula Na2O. ______Sodium Oxide___ 14. Write the name for the formula NO. _____Nitrogen Monoxide________ 15. Preservatives are considered to be __inhibitors___ because they are added to foods to slow down the rate at which the food spoils. 16. Four factors that affect the rate of a reaction are: a. ____temperature_____ b. ___concentration (how much)___ c. ___surface area___ d. ____presence of catalyst or inhibitor___ 17. Identify by name the polyatomic ion(s) in the compound NH4OH. ____ammonium and hydroxide ___ 18. Phosphate is a ___polyatomic / negative____ ion. 19. The number of _atoms_ of each element in the formula of a compound is written as a subscript number, whereas the __ionic charge / oxidation number / charge number__ of the element is written as a superscript number. 20. A coefficient in front of a formula represents how many ___molecules__ of that formula. 21. Write the formula for the following covalent bonds: a. dinitrogen monoxide __N2O_____ b. sulfur trioxide ___SO3___ 22. Which is an example of a chemical reaction taking place? a fire being ignited by a match or an ice cube feeling cold melting in your hand Why? because whatever is on fire is changing chemically and can’t be changed back 23. When magnesium is added to HCl acid, H2 gas is released. This is an example of a ( physical / chemical ) change because the magnesium and HCl react to create new & different substances and you can’t change them back. 24. Write the chemical formulas for the binary (ionic) compounds. Be sure to reduce if appropriate. a. Calcium Chloride CaCl2 b. Magnesium Oxide MgO (was Mg2O2, but it is reduced) 25. Explain why you would not find Group 1, alkali metals, pure (not combined w/ anything else) in nature. Group 1 metals are highly reactive and want to bond with other elements (they may even explode in the presence of water!)