Which gas has a lower flammability limit of 2.5 and an upper flammability limit of 100 while in air at 25^circ C and 101 kPa? Ammonia Acetylene Ethanol Acetone
All combustion reactions are exothermic. When substances burn they usually give off energy as heat and light. True False
Using Delta G calculate the value of the thermodynamic equilibrium constant K for: H_(2)(g)+Br_(2)(l)- -gt 2HBr(g)
An aqueous solution is saturated in both oxygen gas and potassium iodide at 80^circ C Determine what happens when the solution is cooled to room temperature. Nothing happens. All of the oxygen gas and potassium iodide remain dissolved in solution. Potassium iodide precipitates out of the solution. Oxygen gas bubbles out of the solution and potassium iodide precipitates out of the solution. Oxygen gas bubbles out of the solution.
Lucy: What's up with the other elements that are in group 8, like Krypton. Do they have anything in common? a) They have the same number of electron shells b) They have the same number of protons c) They have the same atomic mass d) They have the same number of valence electrons
Multiple Choice Question Salt is __ chloride by weight. 40% 50% 60% 70%
Calculate the cell potential, E_(cell) for the reaction below when [Cr^3+]=0.25M and [Pb^2+]=0.15M 2Cr(s)+3Pb^2+(aq)leftharpoons 2Cr^3+(aq)+3Pb(s) E_(cell)^circ =+0.61V E_(cell)=0.597V E_(cell)=0.573V E_(cell)=1.09V E_(cell)=1.21V E_(cell)=0.871V
What term describes a solution where a solid dissolves in a liquid? soluble insoluble immiscible indissolvable
6) When 2,400 mg zinc is added to hydrochloric acid, 450 mL of hydrogen gas forms at a temperature of 30^circ C What is the pressure of the gas (in atm)? underline ( )Zn(s)+underline ( )HCl(aq)arrow underline ( )ZnCl_(2)(aq)+underline ( )H_(2)(g)
5) Determine the pressure (in mmHg) for the nitrogen gas sample that is collected when 53.0 g of NaN_(3) decomposes. The temperature of the gas is 25^circ C and the volume is 18.0 L. underline ( )NaN_(3)(s)arrow underline ( )Na(s)+underline ( )N_(2)(g)
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
