Which action decreases the activation energy of a reaction? decreasing the temperature removing reactant molecules removing a catalyst adding a catalyst

11. Why is titanium dioxide commonly used in sunscreen? It dissolves easily in water It reflects and scatters UV rediation It changes color in sunlight It reacts with skin proteins

Oxyacetylene cutting is a very rapid form of rusting. True or False

10. Which types of bonds tend to have the highest bond energy? 11. Which types of bonds tend to have the lowest bond energy?

Part 1: In the space below, use the periodic table and show how to calculate the molar mass of water $(H_{2}O)$ and oxygen gas $(O_{2})$ Molar mass of H2O: $H_{2}O:\underline {\quad }g/mol$ Part 2: Balance and classify the reaction for the creation of oxygen gas $(O_{2})$ from water $(H_{2}O)$ Fill in the blanks to balance the chemical reaction below: What type of reaction is this? (circle the correct answer) a. Single Replacement b. Double Replacement c. Combustion d. Decomposition $\underline {\quad }H_{2}O(l)\rightarrow \underline {\quad }H_{2}(g)+\underline {\quad }O_{2}(g)$ Molar mass $O_{2}:\underline {\quad }g/mol$

At room temperature and pressure, the distance between gas particles is about __ times the diameter of the particles themselves. a two b fifty c one hundred d ten

4 7 Add an answer item! Add an answer item! Answer Bank carbon iodine

10. What is the mole ratio of $MgCl_{2}$ to HCI $\underline {\quad }:\underline {\quad }$

Which action effectively increases the reactant concentration and increases the reaction rate? decreasing pressure heating the reactant mixture increasing pressure cooling the reactant mixture

What mass of HCl is needed to generate 452 g of $AlCl_{3}$ ? $2Al+6HCl\rightarrow 2AlCl_{3}+3H_{2}$ $AlCl_{3}:133.33g/mol$ $HCl:36.46g/mol$ $[?]gHCl$

Matter can undergo physical or chemical changes. Which of these are examples of chemical changes? Select TWO correct answers. A. Freezing water B. Milk souring C. Iron melting D. Dry ice sublimating E. Cooking an egg