shana
Popular questions and responses by shana
Chemistry
need help to balance half reaction in basic solution IO3 to I2
asked on July 27, 2013 
Linear algebra
Find all complex numbers z satisfying z3 = 27i and give your answer as a commaseparated list of values in the form a+bi.
asked on March 30, 2017 
Chemistry
Calcium hydroxide, Ca(OH)2, dissolves in water to the extent of 1.78 g per liter. What is the value of Ksp for Ca(OH)2?
asked on April 22, 2014 
chemistry
Is diphosphorus pentoxide an ionic or a molecular compound? A. Ionic B. Molecular I say B
asked on November 10, 2012 
Linear algebra
please help me with this question I have no idea how to solve it, thanks Suppose T is a transformation from ℝ2 to ℝ2. Find the matrix A that induces T if T is rotation by 1/6π.
asked on March 21, 2017 
Algebra
Let L be the line passing through the point P=(1, −1, −5) with direction vector →d=[−2, −4, 3]T, and let T be the plane defined by −x+y−3z = −1. Find the point Q where L and T intersect.
asked on March 19, 2017 
Chemistry
A 30.00mL sample of 0.150M KOH is titrated with 0.125M HClO4 solution. Calculate the pH after the following volumes of acid have been added: 30.0 mL, 35.0 mL, 36.0 mL, 37.0 mL, 40.0 mL
asked on November 17, 2011 
Chemistry
The following reaction is reactantfavored at equilibrium at room temperature. COCl2(g) > CO(g) + Cl2(g) Will raising or lowering the temperature make it productfavored?
asked on May 1, 2014 
chemistry
When NH3 is treated with oxygen gas, the products obtained are N2(g) and H2O(l). If standard enthalpies of formation at 298 K for NH3(g) and H2O(l) are –46.00 kJ/mol and –286.0 kJ/mol respectively, calculate the enthalpy change of the reaction.
asked on January 27, 2015 
chemistry
When compared to compound B, compound A has lower melting and boiling points and vaporizes more readily. Is compound A an ionic compound or a molecular compound? A. Ionic B. Molecular I say B
asked on November 10, 2012 
chemistry
What is usually indicated by an ite or ate ending in a chemical formula? A. The compound carries a net ionic charge of zero. B. The compound contains a polyatomic ion. C. The compound is an acid. D. The compound is molecular. I think A
asked on November 10, 2012 
math
What is one mole of H2O composed of? A. 2 hydrogen atoms and 1 oxygen atom B. 2 × (6.02 × 1023) hydrogen atoms and 6.02 ×1023 oxygen atoms C. 3 atoms of water and 2 oxygen molecules D. one half of a molecule of peroxide I say A
asked on November 8, 2012 
Linear algebra
please help :( Bob and Doug play a lot of PingPong, but Doug is a much better player, and wins 90% of their games. To make up for this, if Doug wins a game he will spot Bob five points in their next game. If Doug wins again he will spot Bob ten points the
asked on April 15, 2017 
chem
When NH3 is treated with oxygen gas, the products obtained are N2(g) and H2O(l). If standard enthalpies of formation at 298 K for NH3(g) and H2O(l) are –46.00 kJ/mol and –286.0 kJ/mol respectively, calculate the enthalpy change of the reaction.
asked on January 27, 2015 
math
What is the percent by mass of hydrogen in C3H8? A. 8.0% B. 18.2% C. 80.0% D. 81.8% I say B
asked on November 8, 2012 
math
How is percent composition calculated? A. Dividing the mass of each element in the compound by the total mass of the compound and then dividing by 100% B. Dividing the mass of each element in the compound by the total mass of the compound and then
asked on November 8, 2012 
math
If there is a 75.0 g quantity of carbon present in each 100 g of a carbon and hydrogen compound, what is the percent composition of hydrogen in this compound? A. 25 g B. 25% C. 75 g D. 75% I say B
asked on November 8, 2012 
math
What is the percent by mass of oxygen in H2O? A. 11.1% O B. 50.0% O C. 88.9% O D. 95.0% O I think C
asked on November 8, 2012 
math
Solve the following and express the answer in scientific notation:(3.5 x 10^6 / (4.2 x 10^8) A . 8.3 X 10^3 b. 8.3 X 10^3 c. 8.3 X 10^2 d. 8.3 X 10^3 I say A
asked on November 7, 2012 
math
If the density of 1.77 grams of gold is 19.3 g/mL, what is the volume
asked on November 7, 2012 
Word Problem
Can someone help me figure out the equation? I am not good at figuring this out. Investing her bonus. Donna invested her $33,000 bonus and received a total of $970 in interest after 1 year. If part of the money returned 4% & the remainder 2.25%, how much
asked on September 10, 2007 
Leadership
Can leadership be inherited? Do you believe that some people are “born” to be leaders
asked on March 10, 2020 
chemistry
In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 21.0 mi/gal , how many liters of gasoline would you need to buy to complete a 142km trip in Europe? Use the following conversions: 1km=0.6214mi and 1gal=3.78L.
asked on September 19, 2019 
algebra PLEASE help
Bob and Doug play a lot of PingPong, but Doug is a much better player, and wins 90% of their games. To make up for this, if Doug wins a game he will spot Bob five points in their next game. If Doug wins again he will spot Bob ten points the next game, and
asked on April 15, 2017 
Linear algebra
Suppose that the sequence x0, x1, x2... is defined by x0 = 1, x1 = 5, and xk+2 = 3xk+1+10xk for k≥0. Find a general formula for xk.
asked on April 13, 2017 
cell biology
How can we differentiate MMPs from different proteolytic enzymes
asked on April 1, 2017 
Algebra
Find the scalar equation for the plane passing through the points P1=(−3, −5, 5), P2=(1, −6, 6), and P3=(0, −9, 4).
asked on March 19, 2017 
Algebra
can anybody help me with this question please? Let L be the line passing through the point P=(5,Â âˆ’5,Â 3) with direction vector â†’d=[1,Â âˆ’3,Â âˆ’2]T. Find the shortest distance d from the point P0=(âˆ’4,Â âˆ’1,Â 4) to L,
asked on March 1, 2017 
Algebra
I spent hours on this and I still cant figure it out please help me: Let L1 be the line passing through the points Q1=(4, 2, −3) and Q2=(5, 5, −5). Find a value of k so the line L2 passing through the point P1 = P1(3, 7, k) with direction vector
asked on February 20, 2017 
Linear algebra
Let L1 be the line passing through the points Q1=(−2, 1, 1) and Q2=(−4, 4, 0) and let L2 be the line passing through the point P1=(−6, −6, 0) with direction vector →d=[9, 6, 3]T. Determine whether L1 and L2 intersect. If so, find the point of
asked on February 20, 2017 
algebra
Plus or minus of 0.05: As measured in standard deviations, how much is a year of learning in school worth on a test? Please answer with a decimal.
asked on February 27, 2015 
statisics
A major hurricane with wind speeds of 111 per hour or greater. During the last century the mean number of major hurricanes to strike a certain country mainland per year was about 0.45. Find the probability that in a given year exactly one major hurricane
asked on February 1, 2015 
business
If u carry out a SWOT analysis you should know the " O" stands for a) outliers. B) opportunities c) outlines d) oddities
asked on August 19, 2014 
Chemistry
How do I find delta S of 2 Na(s) + 2H2O(l) > 2NaOH(aq) +H2(g)? I tried to find it using this.... ^Srxn= 2S(NaOH)  S(H2) 2S(Na)  2S(H2O) = 2(48.1)130.7  2(51.21)  2(69.95) = 96.2  130.7  102.42  139.9 = 279.82 Where did I go wrong??
asked on May 1, 2014 
Chemistry
Estimate the solubility of calcium fluoride, CaF2+, (a) in moles per liter and (b) in grams per liter of pure water. CaF2+(s) = Ca2+(aq)+2f(aq)
asked on April 22, 2014 
science
why it is important to take care of the eyes and go for a regular checkup?
asked on December 13, 2013 
British literature
How do Falstaff's adventures mirror the main plot in Shakespeare's Henery the 4th
asked on October 25, 2013 
chemistry
pH = 3.89 calculate concentration of hydronium ion and hydroxide ion in solution.
asked on July 26, 2013 
CURRENT PROCD TERMN CODING
wHAT IS THE CODING SYSTEM PHYSICIANS USE TO FILE THEIR CLAIMS
asked on July 15, 2013 
math
Sven is thinking if two numbers. The sum is 12 . The difference is 4. What are the two numbers
asked on March 7, 2013 
math
estimate the sales tax and final cost of a book that costs $12.99 with a sales tax of 6%
asked on January 23, 2013 
chemistry
Which of the following consists of positive and negative ions bound together and held in place in a crystalline solid? A. Covalent bonds B. Ionic compounds C. Molecular compounds D. Molecules I say B
asked on November 10, 2012 
chemistry
Which phase of ionic compounds are good electrical conductors because the ions are free to carry electrical current? A. Solid B. Liquid C. Gas D. Crystalline I say B
asked on November 10, 2012 
chemistry
Which ion is absorbed by a base in water? A. H3O+ B. OH C. Neutron D. Transition metal B
asked on November 10, 2012 
math
When solving for the percent composition of a given compound, the percent of each element in the compound must be found and reported. True false TRUE
asked on November 9, 2012 
math
127.1 g Cu combines completely with 32.1 g S to form a compound. What is the percent composition of this compound? A. 20% Cu; 80% S B. 50% Cu; 50% S C. 80% Cu; 20% S D. 127% Cu; 32% S I say A
asked on November 9, 2012 
math
If there is a 75.0 g quantity of carbon present in each 100 g of a carbon and hydrogen compound, what is the percent composition of hydrogen in this compound? A. 25 g B. 25% C. 75 g D. 75% I say B
asked on November 9, 2012 
math
In order for the percent composition of a compound to be calculated, the molar mass of the compound and the chemical formula must be determined. True False I say true
asked on November 9, 2012 
math
Convert 1,144 oF to oC A. 617.8 B. 617.8 oC C. −617.8 oC D. −617.8 I say B
asked on November 7, 2012 
math
To add numbers using scientific notation, multiply the coefficients and then add the exponents. true or false true
asked on November 7, 2012 
math
Solve the following and express the answer in scientific notation: (5.4 x 10^4)  (2.5 x 10^6) A. 2.45 x 10^6 B. 2.45 x 10^6 C. 2.45 x 10^8 D. 2.44 x 10^2 I say D
asked on November 7, 2012 
math
Solve the following and express the answer in scientific notation: 10^3 x 10^4 x 10^2 A. 10^5 B. 10^6 C. 10^7 d. 10^8 I say A
asked on November 7, 2012 
math
Solve the following and express the answer in scientific notation: (5.3 x 10^4) + (2.2 x 10^3) A. 5.5 x 10^4 B. 7.5 x 10^3 C. 7.5 x 10^7 D. 11.7 x 10^7 I say A
asked on November 7, 2012 
math
The melting point of helium is 272.2 oC. Express this temperature in kelvins. A. 272 K B. 8.0 K C. 0.8 K D. 545 K I say D.
asked on November 7, 2012 
math
what is the mass of 1.00 L of ethanol? Ethanol has a density of 0.798 g/ml. (hint: one liter is 10^3 mL.) A. 0.789 g B. 789 g C. 789 L I think C
asked on November 7, 2012 
math
what is the mass of 12.0 ml of a substance with the density of 0.922 g/cm3? A. 1.11g B. 0.11g C. 11.1 g I think C.
asked on November 7, 2012 
math
what is the specific gravity of a substance that has a density of 1.59 g/cm3? A. 1.59 g/mL B. 1.59 g C. 1.59 D. 1.59 mL I think B.
asked on November 7, 2012 
math
if the density of .88 grams of mercury is 13.6 g/ml, what is the volume? A. 0.065 mg B. 0.065 C. 0.065 ml D. 0.065 L I think its C.
asked on November 7, 2012 
math
If melted butter were poured into a glass of milk and allowed to rest, two distinct layers would be visible. How would these layers appear? A. The melted butter would lie above the layer of milk because butter is less dense than milk. B. The melted butter
asked on November 7, 2012 
math
Mercury has a density of 13.6 g/cm^3. What is the specific gravity of mercury? A. 13.6 g B. 13.6 cm C. 13.6 cm^3 D. 13.6
asked on November 7, 2012 
math
In scientific notation, a number is written as the product of a coefficient and the number 10 raised to a power. True False
asked on November 6, 2012 
math
Solve the following and express the answer in scientific notation: (5.4 × 10^4) × ( 4.5 × 10^8)
asked on November 6, 2012 
english
The following sentence shows what element of poetry? Her fiery eyes swept away his heart. A. Imagery B. Figure of speech C. Personification D. Simile
asked on October 16, 2012 
english
What word best describes the Realist's and Modernist's perspective on the world? A. Objective B. Passionate C. Subjective D. Unemotional
asked on October 16, 2012 
english
Which literary movement consists of honest and open descriptions the setting and characters? I say B. A. American Modernism B. American Realism C. American Romanticism D. American Transcendentalism
asked on October 16, 2012 
MATH
WHAT IS THE SUM OF ALL THE DISTINCT, POSITIVE PRIME FACTORS OF 1260
asked on September 11, 2012 
Chemistry
Calculate the theoretical pH at the starting point and at each equivalence point for phosphoric acid, acetic acid, and sulfuric acid. Please show the equilibrium equation, the Ka, and the pH calculation.
asked on December 12, 2011 
Chemistry
Develop a recipe for 1.00L of pH 4.50 buffer using only 17.4M HC2H3O2 and 3.00M NaOH (and deionized water). Be sure that it can accommodate an addition of at least .50 mol of strong acid or base with a change in pH less than/equal to 1.
asked on December 12, 2011 
Physics
Find the angle that the vector R = A + B makes with the positive x axis, use counter clockwise as the positive angular direction, between the limits of −180 degrees and +180 degrees. Answer in units of degrees
asked on November 18, 2011 
statistics
if a data set has mean 70, and standard deviation 5, is 80 asuspect outliner/
asked on September 15, 2011 
Social Studies
I am an investor in the Virginia Company. What is a reason of why people should leave England and move to Jamestown. What are the two advantages of living in Virginia? Thank you.
asked on September 15, 2011 
math
6.8 in fraction notation
asked on March 13, 2011 
Math 11th grade
How to solve system of equations 5a=5 6b3c=15 2a+7c=5
asked on October 11, 2010 
Chemistry 143
Write three thermochemical equation needed to calculate delta H for the following reaction: 2Mg(s) + O2(g) = 2MgO Include delta h values in kJ for each reaction. Please help!! I don't even know were to start!!
asked on April 26, 2010 
algebra
Trains a and b are traveling in the same direction on parallel tracks. Train a is traveling at 40 mph and train b is traveling at 50mph. Train a passes a station at 12:15 a.m. If train b passes the same station at 12:27a.m. at what time will train b catch
asked on April 14, 2010 
spanish
what dose tengo sed puedo ira
asked on September 10, 2009 
9th grade
what are energy bar graphs?
asked on March 13, 2009 
math
My friend found two old watches. He wound them, set them, and started both of them at the same time. He placed the two old watches on one wrist and his new watch on the other wrist. Fortyfive minutes later one of the old watches had gained 1 minuate and
asked on March 5, 2009 
math
a pickup truck has a main tank with a 17 3/4 gallon capacity and an auxiliary tank which holds 15 1/8 gallons. if the truck gets 14 6/10 mpg, how far can the truck trqavel before running out of gas?
asked on July 28, 2008 
math
Solve the following and express the answer in scientific notation: 10^3 x 10^4. A. 10^1 B. 10^1 c. 10^6 D. 10^7 I say D
asked on November 7, 2012 
science
Does flowers store food?
asked on February 25, 2008 
Algebra
Graph the absolute value inequalities. I just can not get this. Please help! x + 2y ¡Ý 6
asked on September 10, 2007 
College Algebra
Could you please help me with this problem? We are to graph each compound inequality. x ¡Ý 2y and x  3y < 6
asked on September 10, 2007 
Juvenile Delinquency
Compare the adolescence period in the United States with that of other nations. Compare and contrast any ritualistic (rites of passage) behavior used by both Americans and foreign children. Please repost and include the answer or response you have come up
asked on November 11, 2006

Matht
126 is the product of delias height and 7
posted on December 6, 2019 
Linear algebra
Bob and Doug play a lot of PingPong, but Doug is a much better player, and wins 90% of their games. To make up for this, if Doug wins a game he will spot Bob five points in their next game. If Doug wins again he will spot Bob ten points the next game, and
posted on April 15, 2017 
Algebra
Thank you so much
posted on March 19, 2017 
chemistry
i don't know can you please help it is an summative from 32 please
posted on May 22, 2016 
5th grade Math
6+10*2
posted on February 24, 2016 
math
6+10*2 the expression equal 32
posted on February 24, 2016 
math
3+5*2210=6
posted on February 24, 2016 
Math
32.04 x300
posted on December 10, 2015 
Finance
This is the answer to #5Capital Co WACC 14.24%
posted on August 27, 2013 
Finance
THis is the answer to #3 Bell Vineyards 0 $2,000 1 $2,460 2 $2,780 3 $2,986 4 $3,101 5 $3,144 Year 6 to purchase
posted on August 27, 2013 
6 grade Math
estimate the sales tax and final cost of a book that costs $12.99 with a sales tax of 6%
posted on January 23, 2013 
math
think its 13.6 g
posted on November 7, 2012 
Literature (Vocabulary)
charlatan naïve hoax amicable levity fickle mundane
posted on February 24, 2012 
Social Studies
Okay, thank you
posted on September 15, 2011 
College Chemistry
If i combust 1.0kg of octane according to the following unbalanced reaction , how many moles of carbon dioxide should i theoretically produce? 2 C8H18+ 25 O2 > 16 CO2+ 18 H20
posted on April 7, 2011 
Writing
31 Myself 32 who 33 they/their 34 they /their
posted on April 9, 2010