Science Chemistry Help 2!!!?
1. Balance the equation by placing coefficients(NO#) in front of the formulae, include correct states (s, i, g or aq) next 2 each formula in the equations. a) Nitric acid + Barium Carbonate powder ---->> b) Sodium carbonate powder --heat-->> c) Lead(II) nitrate solution + ammonium iodide solution --->> d) Aluminium + oxygen --->> e) Magnesium + sulfuric acid --->> f) Pentane (C5H12) + Oxygen --->> g) Hydrochloric acid + potassium hydroxide solution --->> h) Zinc + copper sulfate solution --->> 2. Describe the tests u would use to identify the following gases: (i) - Hydrogen (ii) - Carbon dioxide (iii) - Oxygen Much appreaciate if you help thank you soo much!!!
Chemistry/science help!!?
2NaCl+2H2O--->Cl2+H2+NaOH # first, find the moles of Cl2(Mr Cl2=71) =mass/Mr =71/71 =1 mol of Cl2 # then, moles of NaCl =coeficient NaCl/coeficient Cl2*moles of Cl2 =2/1*1 =2 mol of Cl2 # finally mass of NaCl(Mr NaCl=58.5) is, mol=mass/Mr ~> mass=mol*Mr so, the mass of NaCl =2*58.5 =117 grams of NaCl ---- hope helps,
Chemistry/Science help?
Doing a review and preparation for a before test assessment, and I'm having trouble with some of the questions: Which is a description of a precipitation reaction? A. Water decomposes to form hydrogen and oxygen. B. Lead combines with oxygen to produce lead oxide. C. Potassium iodide is added to lead nitrate to produce an insoluble yellow solid, lead iodide. D. Sulfuric acid combines with sodium hydroxide to produce water and sodium sulfate. Sulfuric acid combines with sodium hydroxide to produce water and sodium sulfate. A. 2Pb + 2O2 → 2Pb2O3 B. Ld + O2 → Ld2O3 C. 4Pb + 3O2 → 2Pb2O3 D. 4Ld + 3O2 → 2Ld2O3 (i think it's B..?) Which is the properly balanced equation for the process in which iron oxide (Fe2O3) and carbon monoxide (CO) react to produce iron (Fe) and carbon dioxide (CO2) gas? A. Fe2O3 + CO → Fe + CO2 B. Fe2O3 + 3CO → 2Fe + 3CO2 C. 2Fe2O3 + 3CO → 2Fe + 3CO2 D. 3Fe2O3 + CO → 3Fe + 2CO2 A student dissolves some solid sodium chloride in a beaker of water. Which are the solute and the solvent? Choose all answers that are correct. A. solute: water B. solvent: sodium chloride C. solvent: water D. solute: sodium chloride Which statement correctly explains whether or not this equation is a balanced equation? 2H2O2 → 2H2O + O2 A. The equation is balanced because it follows the law of conservation of mass. B. The equation is balanced because its reactants are the same as its products. C. The equation is not balanced because new products were produced. D. The equation is not balanced because it has 1 reactant and 2 products. Thank you soo much.
Chemistry/science help?
in an alkaline solution, the total number of hydronium ions are A. equal to the total number of hydroxide ions B. is greater then the total number of hydroxide ions C. is fewer then the total number of hydroxide ions 2. when substance A is reduced by substance B what happens to substance B? substance A acts on substance B as A. a reducing agent B. oxididizing agent C. a slat D. non of these and last 3. an electric current can be made to flow from A. a reducing agent to an oxidizing agent B. an oxidizing agent to a reducing agent C. an oxidizing agent to another oxidizing agent D. a reducing agent to another reducing agent
Chemistry science help!! 10 points?
International Nature of Chemistry Discuss the international nature of chemistry and why that is significant. Give a minimum of three examples of work from different countries. Chemistry as Foundation of Modern Technology Give two or more specific examples of how modern chemistry has enabled the creation of useful technology. Environmental and Health Impacts of Chemistry Give three or more examples of environmental, health benefits or hazards, which exist from exposures to chemical elements. Discuss why this is important to know and whom it is most likely to affect.
Physical Science Chemistry Help.?
1. Atomic weights: Na=23 O=16 H=1 NaOH=40 2NaOH + 2H2O ===> 2NaOH + H2(g) Two moles Na need only two moles H2O, and you have three moles H2O. So the limiting reagent is Na: It will run out first. 2molNa x 2molNaOH/2molNa x 40gNaOh/1molNaOH = 80g NaOH 2. Atomic weights: C=12 H=1 O=16 CO=28 CH3OH=32 78gCH3OH x 1molCH3OH/32gCH3OH x 1molCO/1molCH3OH x 28gCO/1molCO = 68g CO 3. There areequal numbers of Na's, O's, H's, and P's on both sides of the equation. So mass is conserved, neither created nor destroyed.
12th science chemistry query...Pls help just now...?
Q. It is observed that for every 10degree Celsius rise in temperature rate constant is double.When a chemical reaction is carried out at 300Kelvin and 280Kelvin.The rate constant were found to be K1 and K2 respectively then.......(Give description of your answer) OPTIONS ARE:: (1) K2=2K1 (2) K2=4K1 (3) K2=0.25K1 (4.) K2=0.5K1
Science help!!! (Physics/Chemistry!!)?
As someone who spends quite a bit of time and money to be better educated, I can not in good conscience just give you all the answers to your homework......but I will tell you what you need to know do it your self. -all the items that have chemical formulas are either pure or compounds. -Look up all of the items, if you can find a chemical formula for it, then it is not a mixture. Please don't come on here to get people to do your homework. It does not do you any good.
How does Earth science relate to chemistry?
Chemistry is necessary to fully understand Earth science.Chemistry helps explain why certain minerals are formed where they are, how they are formed, what their structure is, what their properties are.
Easy chemistry/science question?
So contaminated air from the outside wont come in via leaks in the construction of the room.