Category Archives: chemistry

Identify which is the oxidation reaction and which is the reduction reaction.

Question 3: Electrochemical Cell (1 6 points) A high school girl was ready for her big date but discovered with horror that her silver necklace was all tarnished. Having just studied about redox reactions and electrochemical cells in chemistry class, she grabbed some aluminum foil, put it in a dish, and placed her necklace on top of the foil. Then she added some baking soda, a little salt, and hot water. Within a few minutes, her necklace was bright and shiny again. The formula for tarnished silver is Ag2S. Use the equation below to answer the following questions. Ag2S+ Al (s) w AI2S3+ Ag(s) (unbalanced) a. Balance the equation with coefficients. (1 point) b. What makes this an oxidation-reduction reaction? (1 point) c. Write the half-reactions showing the….

What will the sucrose concentration be after 2.0 hours?

Sucrose, C12H22O11, reacts slowly with water in the presence of an acid to form two other sugars, glucose and fructose, both of which have the same molecular formulas, but different structures. C12H22O11 + H2O ? C6H12O6 (glucose) + C6H12O6 (fructose) The reaction is first order and has a rate constant of 6.2 × 10-5/s at 35°C when the H+ concentration is 0.10 M. Suppose that the initial concentration of sucrose in the solution is 0.40 M. What will the sucrose concentration be after 2.0 hours?

What precipitate is formed when solutions of aluminum nitrate and calcium chromate are mixed?

 

1. The formula of chloric acid is HClO3. a) true b) false

2. Bases react with active metals to produce hydrogen gas. a) true b) false

3. Aqueous solutions of acids and bases conduct electricity. a) true b) false

4. The piece of lab equipment shown is used to dispense precise volumes. What is this piece of lab equipment called? a) pipette b) burette c) volumetric flask d) graduated cylinder

5. Which of the following solvents is often described as the universal solvent? a) hydrochloric acid b) water c) ethanol d) carbon tetrachloride

6. Solutions have a fixed composition. This means that the amount of solute in a fixed amount solvent is always the same. a) true b) false

7. 96.3 g of potassium iodate is used….

What precipitate is formed when solutions of aluminum nitrate and calcium chromate are mixed?

 

1. The formula of chloric acid is HClO3. a) true b) false

2. Bases react with active metals to produce hydrogen gas. a) true b) false

3. Aqueous solutions of acids and bases conduct electricity. a) true b) false

4. The piece of lab equipment shown is used to dispense precise volumes. What is this piece of lab equipment called? a) pipette b) burette c) volumetric flask d) graduated cylinder

5. Which of the following solvents is often described as the universal solvent? a) hydrochloric acid b) water c) ethanol d) carbon tetrachloride

6. Solutions have a fixed composition. This means that the amount of solute in a fixed amount solvent is always the same. a) true b) false

7. 96.3 g of potassium iodate is used….

What are the gaps in the existing body of knowledge?

Topic: knowledge regarding Modern and traditional Therapy of Typhoid In Developing countries (3000 words) Instructions: The literature review must contain key references/theorists/researchers for the public health topic chosen. The literature review assignment must be designed to address the following questions: • Who are the key theorists/researchers in your public health topic? • What are the key issues? • What are the gaps in the existing body of knowledge? The literature review should provide a basis for justifying a clear research question or hypothesis to be explored further. You must also indicate the search strategy used for your literature review. For example, what were the key words you searched for, and which key databases or other sources did you use to conduct your literature review? (e.g. CINAHL, Proquest Public….

For each reaction, record your observation

Experiment-6: Double Displacement Reactions – Beyond Labz

The Chem 1A lab manual includes two “classic” experiments that look at reactions of ions in aqueous (water) solution. Experiment-6 looks at what happens when you mix solutions of different ionic compounds together, so that new combinations can form. There are two basic ways that a reaction can occur:

1) A cation and anion combine to form an insoluble product, which makes a solid precipitate

2) The H+ ion combines with an anion to form a soluble, molecular compound.

We’re looking at reactions in water, so all reactants start out as homogeneous, aqueous solutions (aq). If a solid product (a “precipitate”) forms, we indicate this by writing (s) after the formula. Note: (s) means “solid”, NOT “soluble.” Precipitates….