Saturday
December 10, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
Thursday, July 14, 2016 by Mariah

Chemistry
1.06g of Na2CO3 is dissolved in water to make 250cm^3 solution. 10.0 cm^3 of this solution was further diluted to make 500cm^3 of 2nd solution. 25.0cm^3 of 2nd solution reacted with 28.5cm^3 of HCl. Find the concentration of HCl in mol/dm^3
Thursday, July 14, 2016 by Gary

Chemistry
Why water can be used as a solvent in paper chromatography?
Thursday, July 14, 2016 by Steph

Chemistry
Why do different substances have different Rf values ? used in chromatography.
Thursday, July 14, 2016 by Stephenie

pharmaceutical physical chemistry
find the density of NH3 gas at 100celsius when confined by a pressure of 1600mmHg
Thursday, July 14, 2016 by gladiza

Chemistry
The reaction 2NO (g) + 2H2 -> N2 (g) + 2H2O (g) was found to follow the rate law, rate = k[NO]^2[H2]. By what factor will the rate of reaction increase when the pressure of NO gas is increased from 2.0 atm to 3.0 atm? Assume all other conditions are held constant. I'm ...
Wednesday, July 13, 2016 by Mikey

chemistry
How much heat is produced by the complete combustion of 287 g of CH4? CH4(g)+2O2(g)→CO2(g)+2H2O(g)Δ​H∘rxn=−802.3kJ
Wednesday, July 13, 2016 by Anonymous

Chemistry
How many molecules are in 5.2L of carbon dioxide gas?
Wednesday, July 13, 2016 by Joey

Chemistry
What is the test for ammonium formed on hubber process? i need your help
Wednesday, July 13, 2016 by RONALD KAZEYA

Chemistry
hydrogen sulfide reacts with sulphur dioxide to give water and S, balance the equation. if hydrogen sulfide contains 125g, how much S is produced?
Wednesday, July 13, 2016 by Love

Chemistry
hydrogen sulfide reacts with sulphur dioxide to give water and S, balance the equation. if hydrogen sulfide contains 125g, how much S is produced?
Wednesday, July 13, 2016 by Love

Chemistry
If you are asked to make exactly 1.0 Liter of 0.80 M ZnCl2 solution, how many grams of zinc chloride would you need to be massed out? How do I go about solving this problem?
Wednesday, July 13, 2016 by Annie

Chemistry
All the following are necessary parts of a neutralization reaction except A) an acid B) an indicator C) water D) a salt.
Tuesday, July 12, 2016 by Mariah

Chemistry
4.80 dm^3 of chlorine gas was reacted with NaOH solution. a) how many moles of Cl2 reacted b) what mass of NaOCl was formed? c) if the concentration of the NaOH was 2.00 mol/dm^3. What volume of sodium hydroxide solution was required? d) write an ionic equation for this reaction
Tuesday, July 12, 2016 by Gary

Chemistry
Theoretically how many grams of malachite should be formed when 1.5 moles of Copper Sulphate reacts with an excess of sodium carbonate?
Tuesday, July 12, 2016 by Dee

12th grade chemistry
It is required to titrate ethanol solution .Being available a 0.2mol/l potassium dichromate solution and 4mol/l sulfuric acid solution on the presence of a convenient indicator. a)indicate the glassware used for titration. b)give a brief description of the procedure followed ....
Tuesday, July 12, 2016 by andy

chemistry
Two compounds of molecular formula respectively C2H4O and C4H8O produce a yellow orange precipitate by the reaction DNPH. a)is this indication sufficient to write the structural formulas of these two compounds? Explain. b)what identification tests should further be done to ...
Tuesday, July 12, 2016 by angy

chemistry
How many grams of Mg(OH)2 would be produced from 4 mol KOH? if the balanced reaction is MgCl2 +2KOH arrow Mg(OH)2 + 2KCl?
Tuesday, July 12, 2016 by barb

Chemistry
Equation of Mg(OH)2 (aq) + KOH (aq) gives you what ?
Monday, July 11, 2016 by Chris

Chemistry
A student dilutes a solution so that its pH changes from 2.4 to 4.4. 10mL of the original solution was diluted by how many mL?
Monday, July 11, 2016 by Anthony

Chemistry
14 grams of coal undergoes complete combustion in 58 grams of oxygen gas. What volume of gas (measured at 25 degrees celsius and 100 kPa) is present when the reaction is complete?
Monday, July 11, 2016 by James

Chemistry
I may need this broken down step by step to understand this problem thanks. A 20.0% by mass solution of phosphoric acid (H3PO4) in water has a density of 1.114 g/ml at 20℃. What is the molarity of the solution?
Monday, July 11, 2016 by Andrew J. DuBois

Chemistry
If a current of 3.00 A is applied to a cell containing a 400g copper anode, determine the final mass of the copper anode after the cell runs for 48.0h
Monday, July 11, 2016 by Luke

Chemistry
If a solid state lithium battery produced 5.00 mA in 8.25 h, then the mass, in milligrams, of lithium consumed would be?
Monday, July 11, 2016 by Luke

chemistry
QUESTION 11 Ammonia gas is formed from nitrogen gas and hydrogen gas, according to the following equation: N2 (g) + 3H2 (g) Imported Asset 2NH3 (g). If 84.0 g of nitrogen gas is allowed to react with an excess of hydrogen gas to produce 85.0 g of ammonia, what is the percent ...
Monday, July 11, 2016 by Anonymous

chemistry
QUESTION 10 Ammonia gas is formed from nitrogen gas and hydrogen gas according to the following equation: N2 (g) + 3H2 (g) Imported Asset 2NH3 (g). If 112 grams of nitrogen gas is allowed to react with an excess of hydrogen gas to produce 120 grams of ammonia, what is the ...
Monday, July 11, 2016 by Anonymous

chemistry
QUESTION 9 The number of moles of the reagent in excess can be used to calculate the moles of the products of the reaction. TRUE FALSE
Monday, July 11, 2016 by Anonymous

chemistry
When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) Imported Asset MgCl2 (aq) + H2 (g), if 72.9 g of Mg and 146.0 g of HCl are allowed to ...
Monday, July 11, 2016 by Anonymous

chemistry
When 4.2g of NaHCO3 is added to a solution of CH3COOH Weighing 10g, it is observed that 2.2g of co2 is realised into the atmosphere . The residue left is found to be 12g . Show that this observations are in agreement with the law of conservation of mass?
Monday, July 11, 2016 by sid

chemistry
20g of NaHCO3 Treated with 22g of HCl Producing 12g of the residue. What is the amount of co2 Formed ?
Monday, July 11, 2016 by sid

chemistry
When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) Imported Asset MgCl2 (aq) + H2 (g), if 72.9 g of Mg and 146.0 g of HCl are allowed to ...
Monday, July 11, 2016 by Anonymous

chemistry
If chlorine and fluorine react according to the reaction (to balance): Cl2+ F2→ ClF3 And calculate the amount of product and of limiting reagent that remains, when 10 g of chlorine and 30 g of fluorine are reacted to give chlorine trifluoride.
Monday, July 11, 2016 by Anonymous

chemistry
For combustion of 10 grams of C4H10 excess of O2, You are obtained 25 grams of CO2 according to the reaction (to balance): C4H10+ O2→ CO2+ H2O Calculate the reaction yield of the reaction. please,could anyone help me to solve this problem.
Monday, July 11, 2016 by Anonymous

chemistry
In the gaseous phase PCl5 dissociates according to the following equilibrium: PCl5⇌PCl3+Cl2 and Kc=0.8 at 613K .Determine the equilibrium composition when 0.12 moles/L of the three compounds are mixed at 613K.
Sunday, July 10, 2016 by Anonymous

chemistry
100 mL of 0.05 M NH3 solution are added to 60 mL of a 0.1 M solution of the same compound.Determine the concentration of the final solution.
Sunday, July 10, 2016 by Anonymous

Chemistry
A 1.00 g sample of limestone is allowed to react with 100 cm^3 of 0.200 mol/dm^3 HCl. The excess acid required 24.8 cm^3 of 0.100 mol/dm^3 NaOH solution. Calculate the percentage of calcium carbonate in the limestone
Sunday, July 10, 2016 by Gary

Chemistry
Given the following three electron configurations: 1s2 2s2 2p5 How many core electrons does this element have? A. 4 B. 5 C. 9 D. 2
Sunday, July 10, 2016 by Megan

Chemistry
Which of the following atoms would have the highest first ionization energy? A. Li B. Be C. Na D. Mg
Sunday, July 10, 2016 by Megan

CHEMISTRY
A solution of a metal carbonate M2CO3, was prepared by dissolving 7.46 g of the anhydrous solid in water to give 1000cm^3 of solution. 25.0cm^3 of this solution reacted with 27.0cm^3 of 0.100 mol/dm^3 hydrochloric acid. Calculate the relative formula mass of M2CO3 and hence ...
Saturday, July 9, 2016 by DAVID

CHEMISTRY
A 1.575 g sample of ethanedioic acid crystals, H2C2O4. xH20 was dissolved in water and made up to 250cm^3 . One mole of the acid reacts with two moles of NaOH. In a titration, 25.0 cm^3 of this solution of acid reacted with exactly 15.6 cm^3 of 0.160 mol/ dm^3 NaOH. Calculate ...
Saturday, July 9, 2016 by Jack

chemistry
the standard enthalpy of formation, for HCOOH(l)is equal to the standard enthalpy for which reaction?
Saturday, July 9, 2016 by Achan

Chemistry
What is theoretical yield in grams of CO2 formed from reaction of 3.12g CS2 and 1.88g O2?
Friday, July 8, 2016 by Mariah

Chemistry
How many mol of hydrogen present in 16g methane
Friday, July 8, 2016 by Anonymous

Chemistry
Two closed vessels of equal volume both with pressure p1 and temperature t1 are connected to each other by tube with negligible volume. If the temperature maintained of both vessels is then changed to t1 and t2 respectively what is the pressure in the vessels?
Thursday, July 7, 2016 by Yuktee

chemistry
To 100 mL of a 0.1M NH3(Kb=1.8*10-5)solution,200mL of a 0.1M NaOH have been obtained.Calculate the pH of the solution.
Thursday, July 7, 2016 by Anonymous

science,physics,chemistry
According to our theory atomic size should increase in groups from top to bottom but in group 13 Aluminium has atomic radius 143 pm and Gallium has atomic radius 135 pm which is less WHY??????
Thursday, July 7, 2016 by Neh

Chemistry
What is the name for the following coordination compound or ion? Na3[Cr (NH3) NO2 Cl3]
Wednesday, July 6, 2016 by Katrina

Chemistry
In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
Wednesday, July 6, 2016 by Kelly

chemistry
What is the difference between the acid and base notation of a hydroxide? Give an example of the same molecular formula written in acid and base notation.
Wednesday, July 6, 2016 by chris

Chemistry
The specific heat capacity of copper is 0.09 cal/g°C. How much energy is needed to flow into a 10-gram sample to change its temperature from 20°C to 21°C?
Wednesday, July 6, 2016 by Mariah

chemistry
How many grams of dipotassium succinate trihydrate (K2C4H4O4·3H2O, MW = 248.32 g/mol) must be added to 790.0 mL of a 0.0522 M succinic acid solution to produce a pH of 5.872? Succinic acid has pKa values of 4.207 (pKa1) and 5.636 (pKa2). is the pH of the current ...
Wednesday, July 6, 2016 by Melodie

Chemistry
For the following reaction, identify the substance being oxidized and reduced CH4 + 2 O2 = CO2 + 2 H2O
Wednesday, July 6, 2016 by Dylan

chemistry
How many g of H2 is formed from 2.4 g H20 according to the following reaction. 2H2O--->2H2O+O2 I believe the answer is .27g However, I can't understand how to work the problem completely out or one like it, if someone could please explain the formula it would be ...
Wednesday, July 6, 2016 by me

Chemistry
For the following reaction, how many kJ of heat are produceed in forming 225.0 g of NO? 4 NH3 + 5 O2 → 4 NO + 6 H2O ΔHrxn = -906 kJ/mole
Wednesday, July 6, 2016 by Morgan

Chemistry
If the ΔH for H2O(l) → H2O(s) is -6.01 kJ, then what is the ΔH for 2H2O(s) → 2H2O(l)? A -6.01 kJ B. 6.01 kJ C. -12.02 kJ D. 12.02 kJ
Wednesday, July 6, 2016 by Leanne

Chemistry
What is the oxidized substance in the following reaction? Fe + 2HCl → FeCl2 + H2
Wednesday, July 6, 2016 by Dylan

AP Chemistry
Q - An electrochemical reaction occurs between an unknown element and zinc. The half-cell reaction for the zinc is: Zn(s) → Zn2+(aq) + 2e− The cell potential for the reaction is Eºcell = 1.83 V. Is the reaction spontaneous or nonspontaneous? Explain. What is ...
Wednesday, July 6, 2016 by Jessica AP Chemistry

AP Chemistry
Q - Aluminum metal reacts with zinc(II) ion in an aqueous solution by the following half-cell reactions: Al(s) → Al3+(aq) + 3e− Zn2+(aq) + 2e− → Zn(s) Predict the potential of the cell under standard conditions. Predict whether the reaction will occur ...
Wednesday, July 6, 2016 by Jessica AP Chemistry

AP Chemistry
Sodium can be extracted by heating naturally occurring salt until it is molten. An electrochemical process is then used to extract the sodium. Cl2 is produced at the anode, and Na is collected at the cathode. Write the half-reactions that occur at the anode and the cathode. ...
Wednesday, July 6, 2016 by Jessica AP Chemistry

Analytical Chemistry
What volume, in liters, of 1.09 M KOH solution should be added to a 0.102 L solution containing 9.35 g of glutamic acid hydrochloride (Glu, FW = 183.59 g/mol; pKa1 = 2.23, pKa2 = 4.42, pKa3 = 9.95) to get to pH 10.26? Should I start with molar concentrations in the beginning (...
Tuesday, July 5, 2016 by R

Chemistry
What volume of each of the following bases will react completely with 25.00 mL of 0.200 M HCl? a) 0.100 M NaOH b)0.0500 M Sr(OH)2 c)0.250 M KOH please explain and show detail I'm so lost on this problem... thanks!
Tuesday, July 5, 2016 by Chantelle

AP Chemistry
Is determining the excess reactant and limiting reactant an important part of a synthesis reaction? Is it an important part of a decomposition reaction? Explain.
Tuesday, July 5, 2016 by Jessica AP Chemistry

AP Chemistry
Choose a chemical reaction involving two or more reactants. For this reaction, how do you determine which reactant or reactants are limiting? Explain.
Tuesday, July 5, 2016 by Jessica AP Chemistry

AP Chemistry
Suppose you designed an experiment in which you burned a known quantity of magnesium in air. You used the product to determine how many moles of oxygen would react with the known number of moles of magnesium. Why would burning magnesium in air cause a source of error for this ...
Tuesday, July 5, 2016 by Jessica AP Chemistry

Chemistry
What is the required volume of an acid to prepare 2 L of solution a 10% (v/v).
Tuesday, July 5, 2016 by Dylan

chemistry
0.01 mol of H2SO4 is present in its solution. Find the pH of the solution
Tuesday, July 5, 2016 by answer please

CHEMISTRY
What mass of sulphur must be burned to produce 64.0 tonnes of sulphur dioxide. . . So far, I have calculated the molecular mass of SO2( 64.1 ) . and then found out the number of moles of sulphur dioxide. ( 998.4) What to do now?
Tuesday, July 5, 2016 by Clive

chemistry
If potassium chlorate is 80 percent pure ,then 48gram of oxygen would produced from how many gram of potassiumchlorate
Tuesday, July 5, 2016 by biswamohan

chemistry
Decomposition of nitrogen pentoxide in ccl4
Tuesday, July 5, 2016 by viji

Chemistry 1111
To determine the molarity of NaOH solution, student took 3.5 g of KHP (KHP – Potassium hydrogen phthalate; Molar mass = 204.22 g/mol) and dissolved in 50 mL of water and titrated with the given unknown molarity NaOH solution loaded in burette. His burette volume read 1.85...
Tuesday, July 5, 2016 by Lowell

chemistry
0.02 Moles of HCl were added to a buffer solution, prepared by fluxing 20 L of gaseous NH3 and 10 L of gaseous HCl, both measured in normal conditions, in 2L of water. Calculate the pH of the solution before and after the HCl addition. (Kb NH3 = 1.8 * 10-5).
Tuesday, July 5, 2016 by Anonymous

chemistry
Calculate the pH of a solution containing 10 g / L of NH4Cl (Kb NH3 = 1.8x10-5
Tuesday, July 5, 2016 by Anonymous

chemistry
Decomposition of nitrogen pentoxide in ccl4
Tuesday, July 5, 2016 by viji

chemistry
To 100 mL of a 0.1M NH3(Kb=1.8*10-5)solution,200mL of a 0.1M NaOH have been obtained.
Tuesday, July 5, 2016 by Anonymous

chemistry
Determine the pH of a solution containing 1.00 mol/L of HCN (Ka = 5.00×10–10) and 5.00×10–2 mol/L of HCl.
Tuesday, July 5, 2016 by Anonymous

chemistry
Calculate the pH of a solution obtained dissolving 10 g of NH3 and 15 g of NH4Cl in 300 ml of water (Kb NH3 = 1.8 x10-5)
Tuesday, July 5, 2016 by Anonymous

AP Chemistry
The G value for formation of gaseous water at 298 K and 1 atm is -278 kJ/mol. What is the nature of the spontaneity of formation of gaseous water at these conditions?
Tuesday, July 5, 2016 by Jessica AP Chemistry

Chemistry
A 25g piece of an unknown metal alloy at 150 degrees Celsius is dropped into an insulated container with 200 g of ice. Calculate the specific heat capacity of the metal, given that 9.0 g of ice melted. How would you work this out?
Tuesday, July 5, 2016 by Fred

chemistry
Difference between a halogen and a halide? Explain using chemical formulas.
Tuesday, July 5, 2016 by lo

chemistry
Write the balanced chemical equation for the dissolution of magnesium sulphate
Monday, July 4, 2016 by lo

Chemistry
What is the volume in L of 34.0g of Ammonia (NH4) at STP?
Monday, July 4, 2016 by Joaquii

Chemistry
An element crystallizes in a body centered cubic unit cell. The radius of this element is 2.20A , and the density is .991 g/cm^3. how many moles of atoms are within one unit cell?
Sunday, July 3, 2016 by Lexi

chemistry
You need to make a 300 ml of a .37M Na2 SO4 solution. How much Na2 So4 should you weigh out?
Sunday, July 3, 2016 by mika

Chemistry
alculate the amount of energy released in the formation of one mole of MgSe bonds (not lattice energy). The radius of the magnesium ion is 0.65 Å, and the radius of the selenide ion is 1.98 Å. Note that 1Å=10−10m
Sunday, July 3, 2016 by Bob

Chemistry Help Please!
1) You have a protein at 20 ug/ml. Its MW =10,000. What is the concentration in molarity? Show work please! 2) You are asked to make 30 mL of a solution at 0.03M using the 0.10M stock solution. How many mililliliters of water do you use to make this solution? How many ...
Sunday, July 3, 2016 by Kimberly

CHEMISTRY
USING DOT (.) AND CROSS (x) DIAGRAM SHOW THE BONDING IN THE COMPOUND FORMED WHEN HYDROGEN AND OXYGEN COMBINE
Sunday, July 3, 2016 by STEPHEN

chemistry
Calculate number of electrons present in 9.5g of PO4^3-
Sunday, July 3, 2016 by vivek pathak

Chemistry
Calculate the molarity and normality of a solution made by dissolving 50g of Al(SO4)3 to produce 2.5 liter of solution.
Saturday, July 2, 2016 by Jonalyn

Chemistry
What is the kb of a 0.0200 m ( at equilibrium) solution of methyl amine, ch3nh2, that has a ph of 11.40?
Saturday, July 2, 2016 by Dylan

chemistry
Determine the pH of a solution containing 1.00 mol/L of HCN (Ka = 5.00×10–10) and 5.00×10–2 mol/L of HCl. It will be the best for me if you give me the answer of this problems.
Saturday, July 2, 2016 by Anonymous

chemistry
Calculate the pH of a solution obtained by mixing 50 mL of NH3 0.1 M (Kb = 1.8•10–5 mol/L) and 25 mL of HCl 0.2 M.
Saturday, July 2, 2016 by Anonymous

chemistry
Calculate the pH of 0.3 M HCl solution. Calculate the pH when 100 mL of a 0.5 M solution of NaOH are added to 300 mL of the HCl solution.
Saturday, July 2, 2016 by Anonymous

chemistry
Calculate the pH of a solution obtained by mixing of 100 mL of a 10-3 M and 50 mL of a 10-2 M solution of CH3COONa.
Saturday, July 2, 2016 by Anonymous

Chemistry
A 360mg sample of sugar (molar mass of 180 g/mol) is dissolved in enough water to produce 200mL of solution. after the sugar is completely dissolved, you pour 50mL of this solution into a Burnette for use in an experiment. what is the molar concentration of sugar in the sample
Saturday, July 2, 2016 by Jacke

chemistry
Arrange the following groups of atoms in order of their increasing atomic radius: K,Rb,F,B,Be I think its F<B<Be<K<Rb someone can you correct me pls
Friday, July 1, 2016 by lo

Chemistry
Ammonium phosphate and nickel(II) nitrate solutions are mixed, what precipitates out?
Friday, July 1, 2016 by Anonymous

Chemistry
When the equation below is balanced and all coefficients are in the lowest, whole number ratio, the coefficients are: C2H6 + O2 ¨ CO2 + H2O I am currently doing an online worksheet to improve in chemistry and I am not quite understanding how to find the coefficients ...
Friday, July 1, 2016 by Anonymous

Chemistry
When the equation below is balanced and all coefficients are in the lowest, whole number ratio, the coefficients are: Bi + O2 ¨ Bi2O3
Friday, July 1, 2016 by Anonymous

Chemistry
Calculate the normality of 1.5M sulphuric acid
Friday, July 1, 2016 by Nishu

chemistry
how do I prepare 10% HCL from 50% HCL solution
Friday, July 1, 2016 by slindile

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