Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
What is the change in ph after addition of 10.0 ml of 1.0 m sodium hydroxide to 90.0 ml of a 1.0 m nh3/1.0 m nh4+ buffer? [kb for ammonia is 1.8 x 10-5]?

chemistry
a sample of liquid consisting of carbon , hydrogen,oxygen was subjected to combustion analysis 0.5439 g of the compound gave 1. 039 g of co2 0.63469g of h2o dertermine the emperical formula

chemistry
Asprin, C9H8O4, is prepared by reacting salicylic acid, C7H6O3, with acetic anhydride, C4H6O3. The other product is acetic acid C2H4O2, C9h8o4 + C4H6O3 -> C9H8O4 + C2H4O2 when 2.00 g of salicylic acid is heated with 4.00 g of acetic anhydride. If the actual yield of aspirin...

chemistry
Calculate the mass of Mg metal requied to consume 2560g of CO2 in the reaction 2Mg+CO2 → 2MgO + C

Chemistry
What happens if a solid is dissolved in a boiling point or freezing point?

chemistry
Examine the analogy and how it compares a part to a whole. link : chain :: atom : _____ Choose the answers that best complete this analogy. (select all that apply) molecule matter compound proton please help

Chemistry
Order in the increasing value of their polarity? HF NH3 H2O CO2 here i used the scale and got their numbers. HF>H2O>CO2>NH3 am i correct?

Chemistry
Order them considering how easily they hydrolize NCl3 AsCl3 PCl5 BiCl3 I know that BiCl3 here makes a percipitate. so how do we order them? When considering their cations(^3+) we can see that all of them have empty p orbitals.So i think they have equal chance of being ...

Chemistry
How do we order them considering their solubility? CH4 , NH3 , Cl2 , CO2 Ammonia make H bonds with water,which makes it the most soluble. CH4 only have Vander Valls forces. I've heard Cl2 disdolves in considerable amounts in water. So how do we order them? Cl2

Chemistry Help
Calculate the mass of Crystals that will form in 400g of water if the solution is cooled from 55 degree cellcious to 15 degree cellcious?

Chemistry
Calculate the mass of Crystals that will form in 400g of water if the solution is cooled from 55°C to 15°C?

chemistry
How can the concept Independent Variable v Dependent Variable apply in your life? please help

chemistry
you have 20ml of an aqueous solution of 0.2M NaOH. if you add distilled water to this solution until you have 200ml , what will be the concentration? How many times did you dilute it?

Chemistry
Does LiAlH4 perform any kind of a reaction with a triple bond?

Chemistry
Does the reaction rate of a zero order reaction becomes half of its initial value,if the concentration of the reactant becomes half of its initial value?

Chemistry
How many N atoms are there in 0.410 mol of NH3? Would it simply be 0.410 x 6.02x10^23?

chemistry
Methane (CH4) is the main component of natural gas. It is burned for fuel in a combustion reaction. The unbalanced combustion reaction for methane is shown below. CH4 + O2 CO2 + H2O + heat When the reaction is balanced, how many carbon dioxide molecules are produced for every ...

Chemistry
Why is meta-nitro phenol more basic than para-nitro phenol?

chemistry
What is the pH of a weak acid solution that has an [H*] of 2.1×10^6 M?

Chemistry
Calculate the concentration (molarity) of copper(ii) sulfate, CuSO4, in 1L of solution containing 200g Copper-Sulfate-Penetahydrate(CuSO4x5H2O)​?

Chemistry
A stp a certain mass of gas occupies a volume of 790cm3, find the temperature at which the gas occupies 1000cm3 and has a pressure of 726mmhg

Chemistry
A sample of nitrogen gas occupies a volume of 20cm3 at 500k and 760mmhg what will it volume be at 860 mmhg and 400k

Chemistry
130 cm3 of a gas exact a pressure 750mmhg. Calculate it's pressure if it's volume is increased to 150 cm3 at 35 degree Celsius

chemistry
A 1.0 g sample of food reacts with oxygen in a calorimeter containing 500 g of water. The temperature rises 10°C. What is the energy content of the food?

chemistry
Assuming a yield of 26.10 percent calculate the actual yield of magnesium nitrate formed from 42.2 g of magnesium and excess copper(ii) nitrate .

Chemistry-Balancing equations
Write a single, balanced equation for the formation of ozone from the high-temperature reaction of atmospheric nitrogen and atmospheric oxygen.

Chemistry stoichiometry
How many grs of H2SO4 is required to obtain 0.1 molal of 1 kg solution?

chemistry
Calculate the concentration of the chromate ion that should be present at the final point of the titration of 50, 00mL of a solution of KBr 0, 02mol/L with a solution of AgNO3 0, 01mol/L, if the maximum theoretical error for titration is 1.0%.

chemistry
a stp a cartain mass of gas occupies a volume of 790cm3 find the tempreture at which the gas occupies 1000cm3 and has a pressure of 726mmhg.

chemistry
a sample of nitrogen gas occupies a volume of 20cm3 at 500k and 760mmhg what will it volume be at 860mmhg 400k

chemistry
130cm3 of a gas excarts a pressure 750mmhg . calculate it pressure if its volume is increase to 150cm3 at 35oc

Chemistry
Hydrogen gas is a very environmentally friendly fuel source. One factor that is important in determining whether it is used as a fuel source is the cost of production. Use the two equations below to evaluate which reaction requires more energy to produce 1 mol of ​H2(g). ...

Physical Chemistry
26.Use Russell-Saunders LS coupling to derive the ground state levels of (a) Ne (b) F (c) Sc (d) Zr (e) C. 30. a. Construct a Grotrian diagram for the He emission spectrum (shown on the right) and use it to assign as much of this spectrum as you can using the data in the table...

Physical Chemistry
15.The Rydberg constant for the Be3+ ion is 109731 cm–1. Calculate the ionization energy of a ground-state Be3+ ion. 22.How many electrons can occupy the following subshells: (a) 2s, (b) 4d, (c) 6f, (d) 6g, (e) 6h?

chemistry
A hypothetical element has two main isotopes with mass numbers of 71 and 74. If 80.00% of the isotopes have a mass number of 71 amu, what atomic weight should be listed on the periodic table for this element? (answer in AMU).

chemistry
what are the electrolytes in ORS?

Chemistry
Can't we except a white percipitate(ethanoic acid),when ethanoyl chloride is dissolved in water???

chemistry
Briefly explain how the neutrons were discovered.

Physics,chemistry,maths
On turning a corner a car drIver driving at 36 km per hour find a child on the road 55 metre ahead.he immediately applies brakes so as stop within 5 metre. Calculate the retardation produced and the time taken by the car to stop.

Chemistry
Find the number of molecules of sodium bicarbonate present in 5.08 gram

Chemistry
What type of solution are the ff: Honey Hydrogen peroxide Chlorine bleach Lemon water Hair spray Air freshener spray Toothpaste Moth balls

chemistry
how would you prepare 100cm cube of 01M SODIUM CARBONATE AND EXPLAIN THE PROCEDURE

Chemistry
How do we order the folllwing considering how easily they grab H^+ ions, when dissolved in liquid ethanoic acid? 1)OH^- 2)F^- 3)Cl^- 4)Br^- 5)I^- I think the correct order is 5<4<3<2<1,because I^- is strong acid cation and may not like to grab H^+ ions etc.Am I ...

Chemistry
Does a neutral solution always act as a buffer solution?

Chemistry
Do the reaction rate depends on the concentration of catalyst? I googled this and found that the decomposition of H2O2 stops of we add excess MnO2. Are there any other examples like this? Or does this happens with every catalyst when they are in excess or they are in very ...

Chemistry
1)In the reaction O2+2F2--> 2 OF2, F2 is the oxidizer. 2)F can't have positive oxidation states. Does 2 explains the reason for the 1st one or is it because because of F's higher electronegativity?

Chemistry
When comparing the boiling points of two compounds,one is a gas and the other is a liquid,is there anything like the liquid will have a lower boiling point than the solid? The molecular mass of the liquid is lower than the solid and they have the same type of intermolecular ...

Chemistry
a 7.50 by mass aqueous ammonia, NH3,solution has a density of 0.973 g/mol. Calculate molality and molarity? Need your ASAP please :(

CHEMISTRY
GIVEN A 30G OF ALCL3 DISSOLVED IN 250G OF WATER TO CME UP WITH 400ML SOLUTION WHAT IS THE NORMALITY ?

Chemistry
Why do Chloroethanoic acid(s) do not hydrolyze? Is it because it they has(have) Cl atom(s)? But the NH4^+ ions in NH4Cl do hydrolyze. What is the reason for this difference?

Chemistry
Determine the oxidation number of V in the V_4O_12^4− ion given that the oxidation number of oxygen is −2

Chemistry
A chemist makes a solution of K2SO4 by dissolving 21.7 g K2SO4 in water to make 100.0 mL of solution. What is the concentration of SO42− ions in the solution? Assume that K2SO4 is the only solute in the solution. The molar mass of K2SO4 is 174.27 g/mol.

Chemistry-@DrBob222
I apologize for having to bother you again,but I still can't post follow up questions and I can't find the reason.I even tried reinstalling the browsers,and still the same. Anyway you responded to my last post regarding H2 O2 fuel cell, "I agree". So did you mean that you ...

Chemistry
refer to the reaction 2NH3 (g) ↔ N2 (g) + 3H2 (g), and ΔH = 92.2 kJ. 1.What will be the effect on the concentration of H2 if the temperature decreases? A. H2 concentration will decrease. B. H2 concentration will not change. C. H2 concentration will increase. D. H2 ...

Maths,physics,biology,english,arabic,chemistry
Calculate the mass of NaOH required to make 500ml of 0.5 M aqueous solution (Molecular mass of NaOH=40)

Chemistry
State whether the following statements are true or false. The importance of using H2 O2 cell in jet engines; a)because it doesn't release gasses which cause Greenhouse Effect b)because it doesn't release gasses which cause Ozone layer depletion The answer key states b is false...

Chemistry
Question : State whether the following are true or false. SO2 gas changes the colour of a KMnO4(aq) solution They have taken this as false and given the following equation: SO2+H2O+2KMnO4-->K2SO4+MnSO4+H2SO4 (not balanced) But why they have taken this as false when Mn2+ ...

Chemistry
Assume that 50g of KCl is dissolved in 100g of water at 100*C and the solution is allowed to cool to 30*C. How much KCl crystallizes from the solution?

Chemistry
Order the following considering their boiling point in an aqueous solution. 1) pentan-2-one 2) pentan-2-ol 3) 2-aminopropanoic acid The answer key says the order (increasing) is, 1 < 2 < 3 and states 1 only have weak permanent dipole dipole forces and Van der Walls ...

Chemistry
what volume of dilute nitric soln. Of density 1.10 and20% nitric by mass contain 10g of nitric

chemistry
Which is most reactive among the following(a) HCHO (b) CH3CHO (C) CH3COCH3 (D) All are equal

Chemistry
An acetic acid buffer solution is required to have a pH of 5.27. You have a solution that contains 0.01 mol of acetic acid. How many moles of sodium acetate will you need to add to the solution? The pKa of acetic acid is 4.74. Show all calculations in your answer.

Science (Chemistry)
An organic compound contains 49.2% Carbon, and 9.68% Hydrogen and 19.19% Nitrogen. If Molecular Mass of compound is 146. Calculate the Molecular Formula of compound.

Chemistry
If we were asked to order SO2,H2O,CuO and CaO considering their acidity, how do we find what is more acidic from CaO and CuO?

Chemistry
If we are given the ksp of AgCl at 14°C and 42°C,how do we find the ∆H° for the dissociation of AgCl(s)?

Chemistry
Why can't we apply Kd directly to a equilibrium solution of CCl4 and H2O,with CH3COOH dissolved? Do CH3COOH form polymers in CCl4? or are their single molecules of CH3COOH in CCl4?

Chemistry
If we wish to find the molar mass of a pure solid organic compound, which measurement would be most useful and why? A)melting point of the solid B)melting point depression of the mixture of the solid with 1,4-dichlorobenzene C)Heat of combustion D)solubility in water

Chemistry
50 liters cylinder is filled with Ar gas to a pressure of 10130KPa at 30C. How many moles of At gas are in the cylinder

Chemistry
A solution contains I-, Br- and OH- ions. If Ag+ is added, what will the precipitate(s) be?

chemistry
The electronic configuration of manganese is: 1s22s22p63d54s2. a)What is the maximum oxidation state of manganese? b)Explain how the electronic configuration shows that Mn is a transition element

chemistry
Between magnesium carbonate and calcium carbonate, which one is more thermally stable? Explain your answer.

chemistry
Between magnesium carbonate and calcium carbonate, which one is more thermally stable? Explain your answer.

chemistry
Why lattice energy of lithium chloride is more exothermic than that of sodium chloride.

chemistry
Write balanced equations to show the thermal decomposition of calcium nitrate and sodium nitrate.

chemistry
What is the energy of electron 4th exicted state of of be3+ ion if energy of electron in ground state

Chemistry
What makes the strongest cation in water? Al Na Fe K Mg I know that the OH^- ions from water are enough for the Al(OH)3 and Fe(OH)3 precipitates to appear and we've been taught that K,Na compounds are soluble in water too. And Mg(OH)2 needs a higher OH^- concentration to ...

Chemistry
Can we use O2 to identify NO and SO2 from each other? Is it because NO+O2-->NO2; NO2 - brownish gas and 2SO2+O2--2SO3;SO3-blue in colour? Or what is the reason?

Chemistry
Does SO2 also make Ca(OH)2 milk white in colour, like CO2?

Chemistry
What is basic like NaOH,from the following? 1)CH3NH2 2)(CH3)2NH 3)(CH3)3N 4)[N(CH3)4]^-(OH^-) 5) 2,4,6-aniline What is the reason?

chemistry
A BALANCED CHEMICAL EQUATION BTW IRON (Fe3+) and NaOH.

chemistry
what is diluted solution and concentrated solution?

Chemistry
What is the positive valence of Sodium Sulfate? (Na2SO4)?

Chemistry
Is thw positive valence of AlCl3 1 or 3 why?

chemistry
Which of the following would most likely act as a Bronsted-Lowry acid? OH- HCN CCl4 Mg(OH)+

chemistry
the important industrial process for producing ammonia (the Haber Process), the overall reaction is: N2(g) + 3H2(g) → 2NH3(g) + 100.4 kJ A yield of NH3 of approximately 98% can be obtained at 200°C and 1,000 atmospheres of pressure. How many grams of N2 must react to form 1...

college subject=chemistry
Q#2..96g of sulphur reacts with 36g of carbon according to the following equation and produces carbon disulphide 2S + C = CS2 (a) the mass of carbon disulphide (b) the excess amount of the reagent in grams that is left unreacted.

chemistry
Q#2..96g of sulphur reacts with 36g of carbon according to the following equation and produces carbon disulphide 2S + C = CS2 (a) the mass of carbon disulphide (b) the excess amount of the reagent in grams that is left unreacted.

chemistry
1=what is the percntage yeild of carbon dioxide if 4 moles of octane are burnt to produce 1350g of carbon dioxide 2c8h18 + 25o2 = 16co2 + 18h2o

Chemistry
Calculate % of lowering of vapour pressure if 36 g glucose is added in 312g of benzene

Chemistry
We are asked to write the three products of the reaction between CH3COOH and NaHCO3(given one is a gas) They would be, 1)CH3COO^-(Na)^+ 2)CO2(g) And what would be the third product? As NaHCO3 is acidic would that be Na2CO3? Because CH3COO^-(Na)^+ is a weak acid salt and NaHCO3...

Chemistry
How do we order the following,considering their stability when they are in (+3) oxidation state? Al Ga Tl Sc We've been taught that (+3) is the common oxidation state of Sc. And when it comes to Al ,Ha,Tl how do we order them?

chemistry
How many numbers of molecules are contained in 24 litre ccl4? density of ccl4 = 1.59 gm

Chemistry
A 99.99% pure, 0.4903 g sample containing only carbon, hydrogen, and nitrogen is subjected to combustion analysis, resulting in the formation of 1.373 g CO2, 0.2791 g H2O, and 0.1860 g NO. What is the empirical formula of the sample?

Chemistry - Stoichiometry/gases
When 2.38 g of methane burns in oxygen, 119 kJ of heat is produced. What is the enthalpy of combustion (in kJ) per mole of methane under these conditions? Your answer will be in kJ/mol. the Molar Mass of methane is 16.04, so I did 2.38g/16.04=0.14838 mol Then I did 119 kj/0....

chemistry
If a substance has a concentration of 85 mmol/L and gives 3 particles on ionization, what would be its concentration in milliosmoles per liter?

chemistry
2.3g hydrogen react with 29g of oxygen to form water what is the limiting reagent

Chemistry
Determine how many mL of 0.102 mol NaOH solution is needed to neutralize 35.0 mL of 0.125 mol H2SO4 solution.

Chemistry
48.0 mL of Ca(OH)2 solution was titrated with 19.2 mL of 0.385 mL mol HNO3. Determine the molarity of the Ca(OH)2 solution.

chemistry
You have made a buffer solution where you added 9 mL 1M Acetic Acid and 0.82 grams Sodium Acetate and diluted it with deionized water to 100 mL. If the Ka for Acetic Acid is 1.76*10-5 and the molecular weight of Sodium Acetate is 82.03 g/mole, what is the pH of the buffer you ...

Chemistry
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Homework Help: Science