Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
Examine the unbalanced equation. CH4 + O2 → CO2 + H2O What is the best classification for the unbalanced equation's reaction, and why? It is a combustion reaction because carbon dioxide (CO2) is emitted as a product. It is a synthesis reaction because O2 displaces carbon (C...

chemistry
Examine the equation. 6CO2 + __H2O → C6H12O6 + 6O2 In order to balance the equation, what coefficient must be placed in front of H2O 4 6 12 1 please help

chemistry
What volume of distilled water should be added to 500ml of a solution of sulphuric acid to 90% by weight, density 1.81 g.mL-1, to obtain a 10 Molar solution?

chemistry
Calculate how many mg of potassium hydroxy are needed to neutralize 75mg of mefenamic acid .

chemistry
thanks!

Chemistry and @DrBob222
Sorry for the mix up -- here's what DrBob222 posted for the Chm or Chemistry question: What subject is CHR? If you don't label the subjects correctly the proper tutor won't know you need help. This question can't be answered as posted. You need the concentration of the H2SO4 ...

chemistry
How much volume of ethane would be required to produce 1.12 dm 3 of carbon (IV) oxide on combustion in sufficient oxygen? 2C2H6(g)+7O2 -> 4CO2(g) + 6H2O

English
I wrote this sentences. Could you check them. Thanks 1. If you were interested, you could take another course. 2. If I were you, I’d study Norse tales. 3. If he really wanted to go into science, he would take biology and chemistry. 4. I wouldn’t have suggested he take ...

Chemistry
h2so4 is labelled as 9.8 by weight. specific gravity of h2so4 is 1.8. the volume of acid to be taken to prepare 100 ml of 0.18M solution is?

chemistry
two everyday chemical reactions then after you have chosen your two everyday chemical reactions List the two reactions and their chemical equations. Also, state each reaction's type (synthesis, decomposition, displacement, or combustion). please help

Chemistry
why the yield of ester is relatively low? suggest modifications which would improve the purity of ester?

college chemistry
You have a solution that contains 12.0 g of NaCl in 50.0 g of water. Calculate the NaCl concentration in units of... mass percent and mole fraction would the mole fraction be 12/12+50=.1935

chemistry
How many years would it take to fly to the sun on a spacecraft that travels 1,000 m/s? (The sun is 93,000,000 miles away) (USE DIMENSIONAL ANALYSIS)

Chemistry
ISO electrons series S2-,CL-K+,Ca2+ are ions increase and decrease.

unt
chemistry ---- 77=25 to the x power. Can anyone assist.

chemistry
A commercial sample of pyrite (FeS2) is oxidized by bromine and nitric acid. The sulphate obtained is precipitated and heavy in the form of BaSO4. If 0, 331g of pyrite originated 0.813 g of BaSO4, what is the% of sulphur in the studied pyrite? What is the% of FeS2??

Chemistry
Which of the following is an element? A. CI2 B. H2O C. HCI D. NaCI

chemistry
Examine the elements listed below. nitrogen (N), phosphorus (P), arsenic (As) Which of the answer choices accurately describes a common property of these elements? they have the same amount of atomic mass they have the same amount of reactivity they have the same number of ...

chemistry
Evaluate the statement. Bromine (Br) is a halogen. Given the information in the statement, what can be inferred as true about bromine? bromine tends to form covalent bonds when in a chemical reaction with metals bromine has seven electrons and seven protons bromine does not ...

Chemistry
if from 10moles of NH3 and 5moles of H2SO4 allH atoms are removed then find the no. of H2 Molecules Formed

chemistry
Are Si valence electrons shared? Are C valence electrons shared? please help

chemistry
How many valence electrons are shared, gained, or lost by each atom of the six compounds? • N2 • CCl4 • SiO2 • AlCl3 • CaCl2 • LiBr

chemistry 2
Which property of group 2 elements ( magnesium to barium) and their compounds increases with an increasing proton (atomic) number? A)the magnitude of the enthalpy change of hydration of the metal ion B)the pH of the aqueous chloride C)the solubility of the sulphate in water D)...

chemistry
how many valence electrons are shared, gained, or lost in nitrogen?

chemistry
Lists how many valence electrons are shared, gained, or lost by each atom of the 6 compounds?       N2           CCl4             SiO2           AlCl3             CaCl2         LiBr          

chemistry
How many valence electrons are shared, gained, or lost by each atom of the six compounds? • N2 • CCl4 • SiO2 • AlCl3 • CaCl2 • LiBr please help

chemistry
In looking at the trend for electronegativity moving from left to right on the perioidic table, which reason below is the correct explanation of the trend? The nucleus is getting stronger and pulling harder on the electrons. The nucleus is getting weaker and pulling less on ...

chemistry
Which element below has the highest electronegativity? O Se P Sb

chemistry
A stronger nuclear pull causes an increase in electronegativity. True False

chemistry
What type of forces hold the atom together? Remember that the atom contains a nucleus and electrons. nuclear gravitational electrostatic

chemistry
What generalization can be made about the solubility of NaCl? An increase in temperature greatly increases the solubility of NaCl in water. An increase in temperature decreases the solubility of NaCl in water. An increase in temperature has very little effect on the solubility...

chemistry
Ionization energy is _____. the energy an electron needs to absorb in order to leave an atom the amount of energy that holds a nucleus together heat that an atom generates after it is formed from other atoms the energy needed to keep an atom neutral

chemistry
Which electrons are removed from an atom first? the ones closest to the nucleus the outermost electrons any electron can be removed first electrons cannot be removed from an atom

CHEMISTRY
On the ionization energy vs. atomic number graph, the peaks, which are Noble Gases, gradually get smaller. Which statement below would best explain that pattern? A Each successive element on the peaks has fewer electrons and that would make ionization energy less. B Each ...

CHEMISTRY
Zinc is determined by precipitating and weighing as Zn2Fe(CN)6. a. What weight of zinc is contained in a sample that gives 0.348 g precipitate? b. What weight of precipitate would be formed from 0.500 g of Zinc?

chemistry 2
Which property of group 2 elements ( magnesium to barium) and their compounds increases with an increasing proton (atomic) number? A)the magnitude of the enthalpy change of hydration of the metal ion B)the pH of the aqueous chloride C)the solubility of the sulphate in water D)...

chemistry
N2 • CCl4 • SiO2 • AlCl3 • CaCl2 • LiBr Which compounds are ionic and which are covalent?

chemistry
Match the elements to form ionic compounds. please help Cl Na Mg O Be S Li F

chemistry
elements below, indicate how each elements’ valence electrons act in a chemical reaction. Insert an L if an element loses electrons, a G if the element gains electrons, an E if the element can either lose or gain electrons, and a U if the element is generally unreactive. H K...

chemistry
Which statement correctly describes a covalent bond? The atoms' valence electrons combine to form a network of bonds. Valence electrons are transferred from one atom to the other. The atoms' valence electrons are shared between the atoms. All of the atoms' electrons are shared...

chemistry
Examine the scenario. A magnesium (Mg) atom gives one electron to two atoms of another element, and takes on a 2+ charge. The two atoms of the other element each form a 1− charge. As a result, the magnesium ion and the two ions of the other element attract and form an ionic ...

Chemistry
Hello, I have the next problem about solubility and dissociation of ions: Calculate the solubility of FeS in pure water. Ksp = 8 × 10−19. (Hint: The second stage of hydrolysis, producing H2S, cannot be neglected.) This excersice was taken from Schaum's college chemistry ...

chemistry
how is iodine bad for human health

chemistry
Read the description. shiny; ductile; solid at room temperature Which of the elements best fits the description? Helium (He) Carbon (C) Magnesium (Mg) Sulfur (S)

chemistry
β-Galactosidase (β-gal) is a hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides. A 0.474 gram sample of β-galactosidase is dissolved in water to make 0.144 L of solution, and the osmotic pressure of the solution at 25 °C is found to be 0...

chemistry
Which of the statements correctly describes the reactivity of noble gases, according to the octet rule? They have eight electrons in their valence shell, so noble gases are very unreactive. They have eight electrons in their valence shell, so noble gases are very reactive. ...

chemistry
Which of the following statements about alkali metals is true? alkali metals have full valence shells alkali metals form 1- cations alkali metals are very reactive alkali metals form 2- cations please help

chemistry
how is hydrogen both beneficial and detrimental on the human body. please help

chemistry
Examples of materials or substances that can be both beneficial and detrimental at the same time. Give two examples. please help

chemistry
help please?? Assuming 100% dissociation, calculate the freezing point and boiling point of 2.64 m K3PO4(aq). Tf= Tb=

chemistry
Which statement best describes how the periodic table has benefitted society and scientists? It has evolved as new information about the elements has been discovered. It includes a lot of detailed information about the elements in a small space. It allows people all over the ...

chemistry
Examine the three listed elements of Group 13. boron (B), aluminum (Al), gallium (Ga) If boron has two energy levels, then how many energy levels do the other two elements have? Aluminum has three energy levels, and gallium has four energy levels. Aluminum has four energy ...

chemistry
What kinds of elements form covalent bonds? What kinds of elements form ionic bonds? explain please help

chemistry
• N2 • CCl4 • SiO2 • AlCl3 • CaCl2 • LiBr Which compounds are ionic and which are covalent? please help

chemistry
Calculate the mass of oxygen which will be evolved on heating 5g of potassium Trioxochlorate(v)

Chemistry
100.0cm3 of 2.0mol dm-3 hydrochloric acid is mixed with 2.5g of magnesium oxide powder. The mixture is stirred until no further change occurs. The resulting solution still contains excess hydrochloric acid. Calculate the volume of 1.5mol dm -3 sodium hydroxide solution needed ...

Chemistry
100.0cm3 of

CHEMISTRY
Which type of solid is predicted for HCl, Na, CaCl2???

CHEMISTRY
What pressure would be required to form a 0.045 M solution of helium (kH = 3.7 x 10-4 M/atm) at 25 °C????

chemistry
Calculate the mass of solid which will be precipitated when 35g of carbon(iv)oxide are passed through a solution of calcium hydroxide

chemistry
Calculate the mass of oxygen which will be evolved on heating 5g of potassium Trioxochlorate (v)

Chemistry
If 226 g of water is contained in a 311 g alu- minum vessel at 11◦C and an additional 92 g of water at 91◦C is poured into the container, what is the final equilibrium temperature of the mixture? The specific heat of aluminum is 900 J/kg · ◦C and of water 4186 J/kg...

Chemistry
If 226 g of water is contained in a 311 g alu- minum vessel at 11◦C and an additional 92 g of water at 91◦C is poured into the container, what is the final equilibrium temperature of the mixture? The specific heat of aluminum is 900 J/kg · ◦C and of water 4186 J/kg...

Chemistry
A 7 gallon bucket of water of mass 26.502 kg and temperature 100◦C is added to a 62 gallon gallon tub of water of mass 234.732 kg having a temperature of 10◦C. What is the final equilibrium temperature of the mixture? Assume there is no loss of heat to the surroundings. ...

Chemistry
A 300 g glass thermometer initially at 32 ◦C is put into 165 cm3 of hot water at 88 ◦C. Find the final temperature of the ther- mometer, assuming no heat flows to the surroundings. The specific heat of glass is 0.2 cal/g ·◦ C and of water 1 cal/g ·◦ C. Answer in ...

chemistry
why is Collaboration necessary and important for scientific advancement. use an example from the atomic theory please help

chemistry
How do carbon-12 and carbon-13 differ? (select all that apply) they have different amount of electrons they have different amount of neutrons they have different atomic charges they have different mass numbers I know one of them is b please help

chemistry
How is collaboration necessary and important for scientific advancement. use examples from the atomic theory please help

Chemistry
How many moles of calcium carbonate, CaCO3, are in 1.500 L of a 0.40M calcium carbonate solution?

Chemistry
What is the molecular formula of a molecule that has an em formula of CH and a molecular mass of 78.11 g/mol?

chemistry
what substances can affect a waters boiling point? please help

chemistry
hydrogen sulfide gas is bubbled through a solution of iron III chloride state and explain what happens

chemistry
Make a prediction. How do you think adding other substances to the water would affect its heating curve? I already have one I just need one more. please help

Chemistry
How many grams of sodium hydroxide, NAOH, are needed to make up 580 ml of 1.50M sodium hydroxide solution?

Chemistry
A chemical reaction produces 3.75 L of chlorine gas at STP. How many moles of chlorine are produced by the reaction?

Chemistry
Given the equation C3H8+5O2->3CO2+4H2O. 1.)Suppose 1.5 moles of C3H8 will be used, How many moles of H2O and CO2 will be formed? 2.)what volumes (at STP) of O2 and CO2 are involved?

chemistry
A scientist discovers that an atom with a mass number of 14 contains eight electrons. According to the scenario, what is the atom's atomic number? 22 6 8 14 please help

chemistry
Which of the following statements best describes p orbitals? a dumbbell with a ring around it a sphere around the nucleus a four-leave clover two lobes apposing each other Examine the three isotopes of potassium (K) below. potassium-41, potassium-39, potassium-40 Which of the ...

chemistry
Which of the answers choices best describes John Dalton's contribution to atomic theory? he discovered to nucleus he gave future scientist a foundation for understanding how electrons move. he gave future scientist a foundation for understanding how atoms make up matter. he ...

chemistry
individual : identification card :: element : __________ Which of the answer choices best completes the analogy? photon energy level atomic fingerprint electron energy level atomic orbital please help

chemistry
What is the difference between belief and knowledge? 

Chemistry
What is the freezing-point depression of water in a solution of 100g of sucrose, C12 H22 O11, and 500g of water? (Molar freezing point depression constant for water is -1.86°C/m.)

Chemistry university
what is the ph of 50ml buffer solution which is 2M in CH3COOH and 2M in CH3CooNa? 1 Initial PH before the addition of acids and base? 2 What is the new PH after 2ml of 6.00M HCl is added to this buffer? 3 what is the new PH after 2.00ml of 6.00M NaoH is added to the original ...

Chemistry
calculate the amount of heat required to raise temperature of 8.50g of water from 24°C to 29°C

chemistry
If the boiling point temperature of a particular liquid (water)is different from 100degreecelcius.what is likely to be the problem with this water.

Chemistry
The radius of a magnesium atom is 160 pm & its mass is 4.04 X 10^-23 g. What is the density of the atom in grams per cubic centimeter? Assume the atom is a sphere with: Volume= (4/3)*pi*r^3

chemistry
WHAT IS THE RATIO OF THE NUMBER OF MOLECULES IN 71 GRAMS OF CHLORINE TO THE NUMBER OF MOLECULES IN 2 GRAMS OF HYDROGEN

chemistry
1,2 of carbon combined with 0,1 grams of hydrogen to form a compound . a.FIND THE EMPIRICAL FORMULA OF A COMPOUND b.ITS Mr WAS FOUND TO BE 78 ,FIND THE MOLECULAR FORMULA

Chemistry
What is the equilibrium constant for H2CO3(aq)->2H+(aq)+CO3-2(aq)

science-chemistry
Predict and draw the structure of the product of the reaction of the following substrates with the given reducing agent. 2-hexanone mixed with hexanoic acid with (i) NaBH4 (ii) LiAlH4

chemistry
What is observed when excess sulfur dioxide is bubbled into a solution of sodium hydroxide containing red litmus paper

Chemistry
What would be the volmeter reading of the cell of Ni and Cu E Ni2+/Ni= -0.24V E Cu/Cu2+= 0.34 V E cell=E cathode - E anode= -0.24 V - (-0.34 V) =0.10V I think this in incorrect as no answer like this is given

Chemistry
Do Ozone gas decomposite naturally under IR rays?

Chemistry
Is S^(2-) a conjugate base of a weak acid? I think it is not as a congugate base grabs a H^+ ion. am I right?

Chemistry
Is S^(2-) a conjugate base of a weak acid? I think it is not as a congugate base grabs a H^+ ion. am I right?

Chemistry
Is S^(2-) a conjugate base of a weak acid? Shouldn't HS^(-) be the conjugate base,as H2S is the weak acid?

chemistry
A quantity of 85.0 mL of 0.900 M HCl is mixed with 85.0 mL of 0.900 M KOH in a constant-pressure calorimeter that has a heat capacity of 325 J/C. If the initial temperatures of both solutions are the same at 18.24C, what is the final temperature of the mixed solution? ...

chemistry
Knowing that 1 mol of a certain monoprotico acid, HX, contained in 1 litre aqueous solution, this 50% ionized, point the value of its ionization constant.

Chemistry
What volume of dioxygen is required for complete combustion of 2 volumes of acetlyene gas at NTP? Ans is 5 volumes but I m not getting it....

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]?

  1. Pages:
  2. <<Prev
  3. 1
  4. 2
  5. 3
  6. 4
  7. 5
  8. 6
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. 14
  17. 15
  18. Next>>

Homework Help: Science