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December 24, 2014

Search: chemical

Number of results: 3,306

biology
Which of the following is true about the relationship between energy and chemical reactions? Activation energy is required for a chemical reaction to occur. Activitation energy is not necessary in a chemical reaction which releases energy. Chemical bonds are always broken by ...
April 15, 2010 by ballamoney1

Changes in Matter
Which of the following geological changes are physical changes and which are chemical changes? a)formation of a limestone cave b)creation of a canyon by a river c)wearing of rocks by wave action d)destruction of lakes by acid rain e)heaving of the ground by ice formation a = ...
March 22, 2010 by Sara

chemistry
Classify the following properties of ozones as physical or chemical: 1.bluish color 2.pungent odor 3.reactive towards oxygen 4.decomposes to oxygen on exposure to ultraviolet light 5.it is a gas Is this correct? 1.chemical 2.physical 3.chemical 4.chemical 5.phsical
February 20, 2008 by lizzie

chemistry
You react chemical A with chemical B to make one product. It takes 100 grams of chemical A to react completely with 20 grams of chemical B. What is true about the chemical properties of the product? a. the properties are more like those of chemical A b. the properties are more...
February 13, 2012 by student

cost finance
1. X is the manufacture of Mumbai purchased three chemicals A, B and C from U.P.The bill gave the following information: Chemical A: 6000 kgs @ Rs. 4.20 per kg Rs 25,200 Chemical B: 10000 kgs @ Rs. 3.80 per kg 38,000 Chemical C: 4000 kgs @ Rs. 4.75 per kg 19,000 VAT 2,055 ...
August 30, 2011 by Anonymous

Math Lit
One 250mg tablet is made up of chemical A , B, ,C in a ratio 3:2:5. The Pharmacist Has 60mg of chemical B left. How much of Chemical A and C does she need if she uses 60mg of B?
February 9, 2012 by Shanna

Science
We did a experiment in class to recognize chemical change. I don't really get this question: Identify the combinations of chemicals in which chemical changes occurred. If the chemical changes occured in all of the combinations, then what would be a good answer? I get the ...
March 23, 2010 by Sara

Changes in Matter
Which of the following kitchen activities are physical changes, and which are chemical changes? a)cooking bacon-chemical b)making icing-physical c)baking a cake-chemical d)using oven cleaner-chemical e)making whipped cream-physical Please correct me if I'm wrong, thanks
March 22, 2010 by Sara

chemistry
What is the difference between biochemical, pharmaceutical, and diagnostic chemical reactions in healthcare? What is a specific example that exists for each of these chemical reaction types above and why might it be of importance to healthcare professionals? List a balanced ...
May 16, 2014 by slomomo

chemistry
A chemical is placed in a beaker containing 20 g of soil and 500 mL of water. At equilibrium, the chemical is found in the soil at a concentration of 100 mg/kg of soil. The equilibrium concentration of this same chemical in the water is 250 µg/L. Calculate the partition ...
January 21, 2011 by Jazmin

science chemical changes
What is the only way that a chemical change can be undone? With another chemical change?
November 6, 2006 by bob

Chemistry
In stoichiometry, chemists are mainly concerned with a. types of bonds found in compounds b. energy changes occuring in chemical reactions c. mass relationships in chemical reactions d. speed with which chemical reactions occur i thought c?
March 10, 2010 by Ana

science
Will you please check a few more? Physical change, chemical change or both kinds of change? 1. Sodium hydroxide dissolves in water (both) 2. Hydrochloric acid reacts with sodium hydroxide to produce a salt, water and heat (chemical) 3. A pellet of sodium is sliced in two (...
September 12, 2012 by Reed

math
A scientist is mixing a chemical solution for an experiment. The solution contains 3/8oz of chemical and 1/6 ounce saline solution. What is the rate of chemical to saline?
December 18, 2014 by Eli

chemistry
what are some the different types of chemical reactions that occur on a daily basis our lives? wouldnt there be many? eating, taking medications, would emotion be or cause chemical reaction? All of the above. Add breathing. Don't forget the cars we drive, the clothes we wear. ...
February 14, 2007 by key

Chemistry-help
How does a "chemical for synthesis" compare with the same chemical(ACS grade)when used in analytical testing? Posted by candy on Tuesday, January 11, 2011 at 2:10pm. Chemicals are supplied in different grades,e.g. ACS,AR...etc.What do we mean when we say that the chemical is ...
January 12, 2011 by candy

Science
What did Antoine Lavoisier’s experiments demonstrate? a- Atoms always split into pairs during a chemical change. b- Mass is neither lost nor gained during a chemical change. c- Matter can be created during a chemical change. d- Energy is neither lost nor gained during a ...
February 9, 2014 by Steve

Chemistry
You have a chemical sealed in a glass container filled with air. The glass container has a mass of 200.0 grams and the chemical has a mass of 850 grams. The total mass of the setup is 1050 grams. The chemical is ignited by means of a magnifying glass focusing sunlight onto the...
January 23, 2012 by Staci

chemistry
You have a chemical sealed in a glass container filled with air. The glass container has a mass of 200.0 grams and the chemical has a mass of 800 grams. The total mass of the set-up is 1000 grams. The chemical is ignited by means of a magnifying glass focusing sunlight onto ...
August 1, 2013 by Kris

chem help
i just don't know where to begin/how a) Write a balanced chemical equation for: potassium carbonate + magnesium chloride b) Write a balanced chemical equation for: sulfuric acid + calcium carbonate c) Write a balanced chemical equation for: sodium sulfate + calcium nitrate d) ...
January 15, 2013 by thad

Changes in Matter
Which of the following everyday activities are physical changes, and which are chemical changes? a)salting ice on a driveway b)burning leaves c)mixing sand with soil d)composting cut vegetation e)using a glue gun a = physical b = chemical c = ? d = ? e = chemical Please ...
March 22, 2010 by Sara

chemistry
Which of the following properties is a chemical property of phosphorus? Answer a) it burns in air b) it is a white waxy solid c) it melts to form a viscous liquid at 44.1 oC d) Both a and c are both examples of chemical properties. e) a, b, and c are examples of chemical ...
September 6, 2010 by Jack

Chemistry
Are the following physical or chemical: a. dew is dried by the sun a dark cloth is faded by the sunlight c. grape juice is converted to wine d. soap is dissolved in water a.physical b.physical c.chemical d.chemical Physical changes are those in which the substance is not ...
September 9, 2006 by Joe

Chemistry
I wont to get concentartion by using A weight of chemical material and chemical formula.
July 18, 2011 by Haider

biology
what is the difference between a chemical that is an irritant compared to a chemical that is corrosive?
August 21, 2011 by josh

science
What kind of chemical bonding(chemical elemants) occurs in bricks, elastic, and rope
March 15, 2012 by long

chemistry
What is the balanced chemical equation of Shampoo? And what is the chemical reaction of it? Please i need a help ASAP! Thank you!
November 26, 2014 by krisha

scince thanks
is a chemical reaction and chemical change the same if not what is the difference?
October 6, 2007 by bella

Chemical Equations
Starting with nitrogen and hydrogen, millions of kilograms of ammonia are produced every year for use as a fertilizer. Use this info to answer the next 3 questions. Communicate the balanced chemical equation using molecular models. Communicate the balanced chemical equation ...
December 2, 2011 by Fizzylicous

college chemistry
how to make a 1:8 dilution of chemical Y. You have 350 mililiters of chemical Y. how much diluent do you need?
February 21, 2013 by chuck

Minoxidil
So, I'm doing a research project for my chemistry class, and one of the parts that I have to answer is the chemical reaction of the substance that I'm researching. But there's a problem. I've searched every single website regarding minoxidil, but I cannot find a chemical ...
May 28, 2012 by Jude

General chemistry
Discuss in detail the healthcare applications of chemical reactions. Which chemical reactions would you consider to be of importance to healthcare professionals? Why? In which situations are these chemical reactions useful to healthcare professionals?
January 3, 2012 by Norma

general chemistry
Discuss in detail the healthcare applications of chemical reactions. Which chemical reactions would you consider to be of importance to healthcare professionals? Why? In which situations are these chemical reactions useful to healthcare professionals?
January 4, 2012 by Norma

Chemistry
The ripening of a banana in which the skin turns yellow and it tastes sweet is an example of what change??? physical or chemical????? Chemical.
April 19, 2007 by Anonymous

chemistry
how is a chemical mixture distinguished from a chemical compound?
March 3, 2008 by anthony

physics
We use many chemicals in our daily lives. How can these chemicals affect you and what can you do to minimize these effects? The chemical industry is enormous in the industrialized world. How has society benefitted from advances in the chemical industry? What negative effects ...
September 20, 2010 by Anonymous

chemistry
In terms of chemical bonds and electrons, what kinds of changes occur between atoms when substances undego chemical reactions?
November 24, 2008 by Akshay

science
__________ rocks forms when a rock is changed by heart,pressure, or chemical reactions. a) Igneous b) Sedimentary c) Metamorphic d) Chemical
January 8, 2014 by Victoria

chemistry
Discuss in detail the healthcare applications of chemical reactions. Which chemical reactions would you consider to be of importance to healthcare professionals? Why? In which situations are these chemical reactions useful to healthcare professionals?
June 25, 2011 by mema

CHEMISTRY
Discuss in detail the healthcare applications of chemical reactions. Which chemical reactions would you consider to be of importance to healthcare professionals? Why? In which situations are these chemical reactions useful to healthcare professionals?
July 21, 2011 by anne

chemistry
Discuss in detail the healthcare applications of chemical reactions. Which chemical reactions would you consider to be of importance to healthcare professionals? Why? In which situations are these chemical reactions useful to healthcare professionals
September 22, 2012 by sonwia

Biology
Which process may not reduce the toxicity of a chemical in the body? Sequestration Chemical bond formation Elimination Blood flow to tissue/organ
October 22, 2010 by Anonymous

integrated physics and chem
Element A and element B have bonded and formed compound AB. Which of the following statements is true? A. Compound AB has chemical and physical properties that are completely different from those of A and B. B. Compound AB has chemical and physical properties that are a blend ...
January 10, 2014 by Anonymous

Economics-HELP!
1. Consider testing of chemicals for potential carcinogens. To properly test each chemical costs $10 million. If Q chemicals are tested a typical household places value $(1 - 0.01×Q) on each chemical tested. There are 100 million households in the U.S. (a) Calculate the social...
November 23, 2009 by anonymous

Chem Lab
Am I right? Classify the following properties of sodium metal as physical or chemical: •Silver metallic color—physical property •Turns gray in air—physical property •Melts at 98º C-melting point is physical property •Reacts explosively with chlorine gas—chemical property ...
April 23, 2010 by Help1001

chemistry
I did an experiment where i used straws and water to simulate a chemical equilibrium. what other differences are there between a real chemical equilibirum and my exeriemtal one.
October 8, 2009 by ana

Chemical engineeing
Can someone help me with online exam ( fundamental of chemical engineering class ) ? Please eamil me ( davd_jo(at)(ya h o o )dot (com ) I'll offer money
May 6, 2013 by Dave

science
What properties of carbon explain carbon's ability to form many different macromolecules? What happens to chemical bonds during chemical reactions? Describe the role of energy in chemical reactions what are enzymes, and how are they important to living things? describe how ...
September 30, 2009 by alec

Math
A scientist is mixing a chemical solution for an experiment. The solution contains 3/8 ounce of a chemical and 1/6 ounce saline solution. What is the unit rate of chemical to saline solution?
April 5, 2013 by Ann

science
I did a hydrate lab in school and these were my results and at the end we have to write the correc formula for the hydrate but I know the answer at the end is supposed to be 5H2O so why do I keep getting 4H2O? Can someone double check my work Mass of evaporating dish 35.88 ...
April 1, 2009 by cara

chem
what occurs when an atom of clorine and an atom of hydrogen become a molecule of hydrogen chloride? a a chemical bond is broken and energy is released b a chemical bond is formed and energy is absorbed c a chemical bond is formed and energry is released d a chemical bond is ...
May 17, 2007 by Katie

IPC
Element A and element B have bonded and formed compound AB. Which of the following statements is true? A) Compound AB has chemical and physical properties that are completely different from those of A and B. B) Compound AB has chemical and physical properties that are a blend ...
November 4, 2010 by Kaitlin

biology
I have some questions that relate to table 2.1 which lists the chemical elements that occur naturally in the human body. Similar percentages of these elements are found in most living organisms. a. In what abiotic (non-life) chemical forms are these elements often found in ...
September 10, 2009 by muffy

Biology(Anatomy&Physiology)
1)Which organelle makes most ATP 2)The chemical reaction that joins two amino acids is called 3)In a single molecule of water which type of bond holds the H to the O? 4)Which type of chemical bond results from the transfer of an electron from one atom to another 5)A chemical ...
October 15, 2008 by Stephanie

Chemistry
Describe what hard water is and how a water softening unit works. Provide balanced chemical equations to show how sodium sulphate can remove these ions (Magnesium and Calcium). The first was no problem, but I am having trouble trying to get through the second part balancing ...
July 17, 2012 by Hannah

OChem
Calculate the amount (volume) of 5.25% (wt./vol.) NaOCl solution (commercial bleach) required to oxidize 100 mg of 9-fluorenol to 9-fluorenone. Whenever appropriate, use balanced chemical equations as a part of your calculation. I know that I need to start off with the ...
December 22, 2009 by Sarah

Science
When you boil an egg, the egg "white" changes from clear to white. The egg also becomes "hard boiled." What type of changes are occurring in the egg? A.Chemical B.Neither physical nor chemical C.Physical D.Physical and Chemical
February 5, 2008 by jika

Chemistry
What are charateristic of a ionic bond and a chemical bond? Answered below for characteristics of ionic bonds. I don't understand characteristics of chemical bond since an ionic bond is a chemical bond. Perhaps you can rephrase your question. For my partial answer look on this...
November 30, 2006 by Pretty in Pink

Science
A persistent organic pollutant is estimated to have a half-life of 30y. If 3 tonnes of the chemical exists in a polluted area today, how much of the chemical will remain after 120y.
December 19, 2013 by Lily

chemistry
Which statement best describes what must occur for two atoms to combine to form a chemical bond? A. The electrons of one nucleus must transfer to the nucleus of the second atom for a chemical bond to form. B. The repulsive forces of both nuclei must overcome their attractive ...
December 15, 2014 by Morgan

chemistry
If the molecular mass for a chemical is 64.10 g/mol and the enthalpy of formation is -63 kJ/mol, the heat change will be _____kJ when 10.0 g of this chemical is formed.
February 23, 2009 by tweety

SCIENCE
Is a forest fire a natural chemical change? Please help me find some other natural chemical changes. Thank you!
November 11, 2010 by Pratigya

Biology
Q1. What enzyme could you use to break down the major chemical in the cell wall? A: EDTA but it's not an enzyme Q2. What chemical would you use to break down the major chemical in the cell membrane? A: something like lipases? Please help!!
June 19, 2009 by Scott

Chemistry
f the molecular mass for a chemical is 153.82 g/mol and the enthalpy of formation is -135 kJ/mol, the heat change will be kJ when 10.0 g of this chemical is formed.
February 22, 2010 by Taylor

Chem
f the molecular mass for a chemical is 352.04 g/mol and the enthalpy of formation is -2137 kJ/mol, the heat change will be kJ when 10.0 g of this chemical is formed.
May 17, 2010 by Andrew

Chemistry
If the molecular mass for a chemical is 153.82 g/mol and the enthalpy of formation is -135 kJ/mol, the heat change will be ____kJ when 10.0 g of this chemical is formed.
February 18, 2009 by Anonymous

Chemistry
If the molecular mass for a chemical is 153.82 g/mol and the enthalpy of formation is -135 kJ/mol, the heat change will be_______kJ when 10.0 g of this chemical is formed.
May 14, 2009 by Linda

Chemistry
If the molecular mass for a chemical is 153.82 g/mol and the enthalpy of formation is -135 kJ/mol, the heat change will be _____ kJ when 10.0 g of this chemical is formed.
February 20, 2010 by Stuck

Chem
f the molecular mass for a chemical is 352.04 g/mol and the enthalpy of formation is -2137 kJ/mol, the heat change will be ______ kJ when 10.0 g of this chemical is formed.
May 17, 2010 by Andrew

Chemistry
If the molecular mass for a chemical is 151.97 g/mol and the enthalpy of formation is -1128 kJ/mol, the heat change will be _______kJ when 10.0 g of this chemical is formed.
February 18, 2011 by HELP!

chemistry-chemical equations
How do I write the balanced chemical equation for Copper +nitric acid -> copper(II)nitrate+ nitrogen dioxide + water
November 30, 2014 by Anonymous

SCIENCE HELP PLZZZZZ! ONLY ONE QUESTION!
Which of the following correctly describes how nerve impulses move throughout the body? A. Electrical transmission through neurons and elecrical transmission between neurons. B. Chemical transmission through neutrons and chemical transmission between neutons. C. Chemical ...
January 7, 2014 by Someone

chemistry
URGENT!!! what is the chemical reaction of hyrodgen peroxide + NH3 ... The chemical formula and written formula!!
October 2, 2008 by tiffany

chemistry
The process that uses electricity to decompose chemical compounds/prepare new chemical compounds
April 28, 2011 by Anonymous

SCIENCE
THE PROCESS THAT USES ELECTRICITY TO DECOMPOSE CHEMICAL COMPOUNDS/ PREPARE NEW CHEMICAL COMPOUNDS
May 2, 2011 by SEKAMOTHO

SCIENCE HELP! ONLY ONE QUESTION!
Which of the following correctly describes how nerve impulses move throughout the body? A. Electrical transmission through neurons and elecrical transmission between neurons. B. Chemical transmission through neutrons and chemical transmission between neutons. C. Chemical ...
January 7, 2014 by Someone

chem
Hi..Can you balance these 4 chemical reactions for me please: 1) Cu + 2Ag NO3 2) Zn + Al(NO3)3 3) Cu + ZnSO4 4) Ca + 2HCI Also will a chemical reaction occur in any of these? Thanks so much Stacey
May 11, 2010 by Stacey

Chemistry Lab
If the molecular mass for a chemical is 151.97 g/mol and the enthalpy of formation is -1128 kJ/mol, the heat change will bekJ when 10.0 g of this chemical is formed.
February 11, 2011 by Shawn

chemistry
What is the complete ionic equation for the double displacement reaction: CuNO3(aq) + K2S(aq)= what is the chemical name and formula of this chemical reaction? plsss. need help
October 3, 2012 by shay

science
List at least three physical properties of water which contain numerical values. Describe a chemical proterty of water which involves a chemical reaction.
January 22, 2009 by Yasmin

Chemistry
Is this the right way to write the structual and the chemical formula for propane? P P P P P C C C C P P P P P Pretend that there are bonds in between each of the letters. Chemical Formula: C3P8. Thanks for checking this out.
May 2, 2009 by Hallie

chemistry
Suggest a test chemical that can be added to a water sample to percipitate the lead(II) ions. show a chemical equation for the formation of the percipitate you have chosen.
May 26, 2010 by Penny

science
Chemical fertilizers stimulate plant growth; but if the concentration is too high, they may damage roots. What precautions concerning chemical fertilizers must a gardener take?
January 18, 2012 by Valerie

College chemistry
Need help balancing chemical equation. Complete and balance the chemical equation. Be sure to include the states of the reactants and products. C3H8(g)+O2(g) →
May 4, 2012 by Lance

science
Chemical fertilizers stimulate plant growth; but if the concentration is too high, they may damage roots. What precautions concerning chemical fertilizers must a gardener take?
September 19, 2012 by Anonymous

math
chemistry experiment needed 12.45 grams of chemical to produce one liter of a gas. If Zoe wanted 24 liters of gas, how many kilograms of the chemical will she need?
October 24, 2014 by shantelle

9th grade
how can a egg be a chemical change? How can an antacid tablet be a physical and a chemical change?
September 23, 2010 by Nichole

chemisty
when looking at a chemical equation what are the evidences that a chemical reaction has occured. Or what is the evidence that it has not occured thanks:):) <3
December 8, 2010 by hannah

Chemistry
Give three examples each of household items that have: a. different structures and exhibit different properties b. same chemical make-up composition but a different structure, hence, different properties c. the same properties but with different chemical composition (If ...
July 11, 2013 by Eliza

earth science
how do chemical rocks form, are some types of limestone considered a chemical rock, and what mineral does rock salt crystalize from. thank you if you choose to answer. im so stumped.
October 9, 2008 by ting

geology
Apart from the composition of the rock itself, what climate do you imagine is more conducive to physical weathering? and Chemical weathering? I know physical weathering is from wind and water transporting the eroded rocks and particles. Chemical weathering is water ...
December 15, 2010 by m

earth science
how do chemical rocks form, are some types of limestone considered a chemical rock, and what mineral does rock salt crystalize from? thank you so much if you choose to answer. im so stumped.
October 9, 2008 by ting

ENGLISH, HELP?
In the following sentence, which words should be in quotation marks? Did you read the chapter Chemical Reactions in our science textbook, Understanding Chemistry? A. chapter Chemical Reactions B. Chemical Reactions C. Understanding Chemistry I think the answer is B, as it is a...
February 1, 2013 by JJ

Chemistry
Name four factors that can affect the rate of a chemical reaction. How does the rate of a chemical reaction change in response to a change in each factor? My answer: Four factors that can affect the rate of a chemical reaction are concentration, surface area, temperature, and ...
October 11, 2010 by Anonymous

Chemistry
NiF2(aq)+Fe2(SO4)3(aq) ==NiSO4 (aq) + FeF3 (s) balance each of the following chemical equations. Express your answer as a chemical equation. Identify all of the phases in your answer. Can help me refresh my memory ...
October 16, 2010 by Lisa

chemistry
An explosive whose chemical formula is C3H6N6O6 produces water, carbon dioxide, and nitrogen gas when detonated in oxygen. write the chemical equation for the detonation reaction of this explosive.
January 17, 2011 by Maria

chemistry
I want to make sure I am correct in classifying whether the following properties of hydrogen are chemical or physical. thanks 1. hydrogen will burN in in oxygen to form water. CHEMICAL 2. hydrogen does not support combustion. CHEMICAL 3.hydrogen is usually found combined with ...
April 8, 2014 by david

Chemistry
Hess's law _____. A.) makes it possible to calculate H for complicated chemical reactions B.) states that when you reverse a chemical equation, the sign of H does not change C.) determines the way a calorimeter works D.) describes the vaporization of solids Please help - I ...
March 4, 2013 by Jack

chemistry
Which of the following is an example of a chemical change (change in chemical composition) that involves starting with a liquid and ending up with a gas? Burning gasoline (combustion). Boiling acetone. A pond evaporating. Condensation of steam.
January 29, 2012 by k

Chemistry
I have 2 chemicals, A & B. Note: both do not contain buffer salts. Chemical A expires 1 week later. Chemical B expires next year. I prepare solution C (general laboratory reagent)containing Chemicals A & B. When assigning the expiry date of solution C, does this mean the ...
July 23, 2011 by anne

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