A) Hydrogen bonds are strong enough to confer structural stability, for example in DNA. B) Hydrogen bonds are weak enough to be easily broken (weaker than covalent bonds). C) They contribute to the water solubility of many macromolecules. D) All of the above Answer: D Page Ref: Section 5 27) London dispersion forces are attractive forces that arise due to A) infinitesimal dipoles generated by the constant random motion of electrons. B) permanent dipoles of molecules containing covalent bonds between atoms of very different electronegativities.
As long as the electronegativity difference is no greater than 1.7, the atoms can only share the bonding electrons. An example of a covalent bond would be water, its two hydrogen atoms with one oxygen atom (H2O). If two atoms differ considerably in their electronegativity than one of the atoms will lose its electron to the other atom. This results in a positively charged ion (cation) and negatively charged ion (anion). The bond between these two ions is called an ionic bond.If the electronegativity difference is greater than 1.7 then the higher electronegative atom has an electron attracting ability which is large enough to force the transfer of electrons from the lesser electronegative atom.
We resulted that lead, silver, and copper are the strongest oxidizing agents, and that magnesium and zinc are the weak oxidizing agents. The strong oxidizing agent oxidized the weak oxidizing agent and in turn the strong oxidizing agent got reduced while oxidizing the weak agent. When a reaction occurred, the solid metal reduced the ion, and in turn made it the more reactive metal. In part two we used a solvent extraction technique to derive an activity series for the halogens. With the use of this technique we placed chlorine, bromine, and iodine into solutions containing chloride, bromide, and iodide.
high melting point, hard, brittle, slightly soluble in water, conductor of electricity when melted or in solution Molecular solid - crystalline solid that has molecules arranged in a particular configuration. low melting point, generally insoluble in water, nonconductor of electricity. Metallic solid - crystalline solid that has atoms of metals arranged in a definite pattern. low to high melting point, malleable, ductile, conductor of electricity, insoluble in most solvents. Lesson 13.6 Changes of physical state: * necessary to draw a temperature-energy graph to see the change in temperature with a constant application of heat Heat of fusion - the amount of heat required to melt 1.00 g of substance.
When the hydrate is heated, it easily loses water molecules attached and becomes an anhydrous salt. The corresponding chemical reaction for hydrated magnesium sulfate can be written as |MgSO4•7H2O ( MgSO4 + 7H2O |(1) | where MgSO4 is the anhydrous salt. Usually,
It goes straight to a gas state, bypassing the liquid state. Sublimation plays a big role for dry ice. Sublimation is the state change of a material from a frozen form to a gas. Sublimation is a direct process from ice. Deposition is known as the opposite process of sublimation.
The solubility of the solution containing Ca(OH)2 in NaOH had a smaller solubility of 4.15 g/L than the solution containing Ca(OH)2 in water, which had a solubility of 4.45 g/L. This experiment successfully showed the relationship between the concentration of the Ca2+ ions in solution. Introduction: Many ionic compounds are considered to be “insoluble” in water, but no compound 8placed in water. When the slightly soluble compound stops dissolving the ions in the solution and the undissolved solid are in equilibrium.  A saturated solution is one that holds as much dissolved solute as possible at a given temperature, therefore only a small amount of a slightly soluble ionic compound is needed to produce a saturated solution of that compound.
Where did the heat the flow from (What happened to the temperature of the ice after salt was added?) 3. What is the minimum temperature that pure water can exist as a liquid at standard pressure? 4. What do you think would happen to the temperature of the ice if you added 6 tablespoons of salt instead of 2 tablespoons?
The salt in this experiment forces its way into the ice cube, therefore bonding with small particles of the ice molecules to raise the freezing point. Since the salt has a higher concentration then the ice causing the ice to dry and become hard to melt. The sugar intrudes the
- signs of chemical change = changes the shape and color, creates a gas, distributes heat, Etc. - Chemical Change= Substance is formed into a completely new substance 2. Hypothesis: If the copper is being tested in these metals ( Copper, Magnesium and cupric chloride) then it would be the least reactive out of magnesium and zinc because it is the lowest among the three on the activity series. 3. Experimental Design: - Independent Variable: different types of metals: magnesium, zinc and Copper - Dependent Variable: amount of reactants observed for each metal - Control : The Air -Constants: The amount of chemical solutions, the time the metals were in the chemical solutions and size of each metal during the experiment 4.