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Questions in chemistry

[Done] Write a claim, evidence, reasoning statement to answer the questions below based on the measurements and observations recorded during the lab. Questions: 1. How does solubility for a gas vary with temperature? 2. How does solubility for a solid vary with temperature? Some sample data similar to the lab is given below. Oxygen in Water \begin{tabular}{|c|c|} \hline \begin{tabular}{c} Temperature $ left({ }^{\circ} C \right)$ \end{tabular} & \begin{tabular}{c} Concentration $( mg$ solute/ mL solvent \end{tabular} \\ \hline 5 & 0.12 \\ \hline 15 & 0.10 \\ \hline 25 & 0.08 \\ \hline \end{tabular}

[Done] If the activation energy required for a chemical reaction were reduced, what would happen to the rate of the reaction? A. The rate would increase. B. The rate would decrease. C. The rate would remain the same. D. The rate would be zero.

[Done] Write P if it describes Physical Change and C if it describes Chemical Change. 1. Hot bottle cracking when placed in cold water. 2. Digesting food 3. Frying chicken 4. Boiling water for soup 5. Rusting of iron 6. Crumpling of paper 7. Rotting meat 8. Burning of wood 9. Rusts 10. Chopping of fruits

[Done] What does percent composition tell you about a molecule? A. It tells you how the elements are arranged in the molecule. B. It tells you the ratio of elements in the molecular formula. C. It gives you the total number of atoms in the molecule. D. It tells you how much of a molecule is made up of each element.

[Done] Which column of the periodic table contains only nonmetals? A. 7A B. 3A C. 5A D. 4A E. 6A

[Done] Which substance is a compound? A. water B. gold C. oxygen D. hydrogen

[Done] 5. Which one of the following can be used as an acid-base indicator for a visually impaired student? a) Litmus b) Turmeric c) Vanilla essence d) Petunia leaves. 6. a) Acids and bases that you encounter in day-to-day life (any 3 from each). b) One strong acid and one weak acid. 7. a) Acid present in car batteries b) An antacid.

[Done] From the reaction given below, write an ionic equation to show which substance is oxidized and reduced. a. [tex]Na ( s )+ CaCl _2[/tex] (aq) i. substance oxidized ii. substance reduced b. [tex]K ( s )+ AgNO _3( aq )[/tex] i. substance oxidized ii. substance reduced c. [tex]Mg ( s )+ CuSO _4( aq )[/tex] i. substance oxidized ii. substance reduced Balance the equation if necessary.

[Done] Complete combustion of a 0.350 g sample of a compound in a bomb calorimeter releases 14.0 kJ of heat. The bomb calorimeter has a mass of 1.20 kg and a specific heat of [tex]$3.55 J /\left( g _{ i }{ }^{\circ} C \right)$[/tex]. If the initial temperature of the calorimeter is [tex]$22.5^{\circ} C$[/tex], what is its final temperature? Use [tex]$q=m C_p \Delta T$[/tex]. A. [tex]$19.2^{\circ} C$[/tex] B. [tex]$25.8^{\circ} C$[/tex] C. [tex]$34.2^{\circ} C$[/tex] D. [tex]$72.3^{\circ} C$[/tex]

[Done] How does your body make this life saving trade? Your blood contains a buffer called sodium bicarbonate (NaHCO3). This weak base, produced in your body, is the same compound that is sold in the grocery store as baking soda. This compound reacts in an exchange reaction with strong acids to produce weak acids that contribute fewer hydrogen cations to a solution. Converting hydrochloric acid produced in your stomach to a weak acid raises your blood pH preventing acidosis. Complete the reaction below by writing the name of the weak acid in the blank. HCl + NaHCO3