Which of the following describes a substance in the solid physical state? The substance compresses significantly. The substance has a variable volume. The substance has a variable shape. all of the above none of the above
Which of the following is an example of a physical change? changing color releasing heat forming an insoluble solid dissolving a substance none of the above
Which of the following processes produces a decrease in the entropy of the system? D dissolution of solid KCI in water D melting ice to form water D boiling water to form steam mixing of two gases into one container D freezing water to form ice
Only about 25% of useful energy is produced in combustion (cars) True False
Question 2 Describe the difference between molecular and ionic compounds. square
Mixture A was made by mixing different components together but it appears to have one phase. Which term best categorizes mixture A? colloid solution emulsion suspension
Which of the following are the reactants of the chemical equation 2H_(2)+O_(2)... 2H_(2)O O_(2) C_(3)H_(13) H
Hexane, C_(6)H_(14) would have which of the following fragments in its mass spectrum? Check all that apply. (m)/(z)=32 (m)/(z)=57 (m)/(z)=29 (m)/(z)=43
Which neutral atom has the following electron configuration: 1s^22s^22p^63s^23p^64s^23d^104p^65s^24d^105p^66s^2 Enter the chemical symbol for the element. View Available Hint(s)
Calculate the density in grams per liter of HF at STP. Be sure your answer has the correct number of significant figures. Note: For molar mass calculations, round to the hundredths place. square (g)/(L)
Explain why the valence electrons are important in determining the chemical properties of an element. They are involved in chemical bonding. They determine the element's color. They determine the atomic mass. They are located in the nucleus.
8. Arrange the following molecules in order of increasing boiling points: $CH_{4},CO_{2},HF,NaCl,Kr,PH_{3}$
4x A chemical reaction for the reaction of Sodium Hydroxide $(NaOH)$ and Hydrochloric Acid (HCl)is shown. The masses of some of the reactants and products are given in grams. $NaOH+HCl\rightarrow NaCl+H_{2}O$ 16g 24912g ? How many grams of water were produced in the reaction? A 189 B 289 C 409 D 529
3. In the lab what was the mass of the steel wool after burning? 1.5149 1.426 g 23479 2.7649 4. Why does steel wool burn, but not an iron rod? The steel wool increased the surface area between reactants, which increased the rate of reaction. The steel wool decreased the surface area between reactants, which decreased the rate of reaction. 5. Why does the steel wool weigh more after the reaction? because oxygen was added during the reaction. it didn't weigh more because energy was created
1. What factors affect reaction rates? Mark all that apply the surface area of reactants the temperature of systems the concentration of reactants presence of a catalyst color of the reactants In the lab , what was the mass of the steel wool before burning? 1.426 g 2.571 g 5.328 a
Marie is learning about the differences between physical and chemical changes in her physical science cuss Which of the following of the house of everyone is occurred? Having a sliced apple turn brown when exposed to air due to oxidation is a physical change Because a new substance has not formed you stall have an appe Heating a piece of metal in a furnace until it glows brightly is a chemical change because the color and appearance of the metal has changed Adding sugar crystals to water to form a clear, colorless liquid is a physical change because the sugar crystats can be separated from the lagued and returned b It's engineer lives. Heating a block of ice to form a liquid is a chemical change because the state of matter has changed from a solid to a bqux1.
Balance cherical reaction equalions Determine mole ratios from a balanced chemical maction equation. Vatue: 4 Seled the comed coeficient to balance the chemical reaction below. $Mg(s)+O2(g)-2MgO(s)$
3. Whattype of resction occure during this experiment? double replacement oxidation reduction (redox) reversible none of the above
Biochemistry A Final Exam Answer the following questions using the drop down menus below: What force makes protons not want to be together? $\square $ Is this force attractive or repulsive? $\square $ Nuclear Force
Aqua Sci Fall MidTerm 2023 A Thinking about how chlorine ne is added to tap water to disinfect the water, what does the quote "The dose makes the polson" mean"? some substances can be toxic/harmful if used in large amounts but may not be toxic/harmful in small amounts 6 $\square $ the poison is about the substance, not the amount $\square $ no one should drink chlorine no matter how small the amount $\square $ waler is water, doesn't matter what dose of substances are in the water POSSIBLE POIN
