1. science

Calculate the number of ions present in 7.45 grams of potassium oxide. ( At.mass of K= 39u).

2. Chemistry

Write the net ionic equation for the precipitation of zinc carbonate from aqueous solution:

3. Chemistry

Write the net ionic equation for the precipitation of iron(II) sulfide from aqueous solution:

4. Chemistry

Write the net ionic equation for the precipitation of manganese(II) carbonate from aqueous solution:

5. Chemistry

Expressing amounts of energy in different energy units is necessary to solve many chemistry problems. For practice, complete the following table. FILL IN THE BLANKS PLEASE. The Joule (J) is the SI unit of energy. 1 calorie (cal) = 4.184 J J cal kJ 695 ___

6. maths

Find the quotient of 4 7 and 3 5 . Give your answer as a fraction in its simplest form.

7. History

1: Part one: What are some facts about Plessy v. Ferguson? *I know that Plessy v. Ferguson is an example of judical review where citizens challenged a law through courts.* Part two: What are the case outcomes and significance? *I think its that when the

8. Math

If m∠FCG = 9x + 3 and m∠GCB = 13x – 9, find m∠GCB

9. Biochemistry

You are asked to make 50 mM Tris-HCl pH 7.5. The pK of Tris is 8.1. What is the concentration of the components (Tris and Tris-H+) in the final buffer solution?

10. Physics II

Two long straight parallel wires separated by L2 = 8.16 cm carry currents of equal magnitude but heading in opposite directions. The wires are shown perpendicular to the plane of this page. Point P is L1 = 1.96 cm from wire 1 and the magnetic field at

11. Maths

The temperature at 6pm of town was 37 degree c at mid night the temperature was 31 degree c if the rise in temperature per hour

12. Science

10 examples for suspension

13. Physics

The greatest and least resultant of two forces acting at a point are 16N and 4N.if they are acting at an angle 120 with one another their resultant is

14. Chemistry

A dime is found to have a mass of 2.33 grams. Using unit analysis, show what the mass of this dime is in kilograms. 2.33 grams x ________ _______ (number) (unit) ________________________________________________ ________ ________ (number) (unit) = ? ___ kg

15. Geometry

To the nearest tenth, find the perimeter of ΔABC with vertices A(2,4), B(-2,1) and C(2,1). Show your work.

17. math

Answer to this questions Please *Question 8* A clock strikes once at 1 o’clock (am or pm), twice at 2 o’clock (am or pm), thrice at 3 o’clock (am or pm) and so on. How many times will it strike in 24 hours? Select one: 1. 78 2. 136 3. 156 4. 196

18. Chemistry

How many milliliters of an aqueous solution of 0.138 M potassium nitrate is needed to obtain 19.4 grams of the salt?

19. Biochemistry

You are asked to prepare 2 L of 50 mM sodium phosphate pH 7.0. The pK2 of phosphate is 6.8. What are the amounts of sodium phosphate mono basic monohydrate (NaH2PO4 • 1H2O, MW=137.99 Da) and anhydrous sodium phosphate dibasic (Na2HPO4, MW=141.96 Da) that

20. Chemistry

You need to make an aqueous solution of 0.233 M magnesium nitrate for an experiment in lab, using a 125 mL volumetric flask. How much solid magnesium nitrate should you add? (fill in blank) __ grams

21. Chemistry

How many meters are there in one picometer?

22. Chemistry

Find active mass of 4gm of H2. Please solve it and explain it.

23. math

A card is selected from a deck. Find the following probabilities. A standard deck of cards has 52 Cards. There are 13 values and 4 suits. Suits are Spades, Clubs, Diamonds and Hearts. Each suit has 13 cards. There are 3 face cards Jack, Queen, and King. a

24. Physics II

A defibrillator passes a brief burst of current through the heart to restore normal beating. In one such defibrillator, a 47.0 μF capacitor is charged to 5.91 kV. Paddles are used to make an electrical connection to the patient's chest. A pulse of current

25. Math

If three teachers can grade 40 tests in 3 hours, how many hours will it take 12 teachers to grade 480 tests?

26. quantitative apptitude

a sum required to earn a monthly income of 1200 at 18% per annum then SI?

27. intro to algebra

Hookes law states that the distance that a spring is stretched by hanging object varies directly as the mass of the object. If the distance is 20 cm when the mass is 3kg, what is the distance when the mass is 5 kg?

28. Math

Can any body please explain A dejuicer was able to squeeze 1/5 of a pint of juice from a bag of oranges. This amount of juice filled up 1/8 of a jug. At this rate, how many bags will it take to fill the entire jug?

29. morgan

A Gantt chart is good for planning but not an effective tool for control. . True False

30. math

Kathy went shopping with a certain amount of money. She spent 1/4 of it on shoes, 1/5 of it on lunch and 78 of it on cloths. She had 21 left. How much money did she have at first.

31. chemistry

How many grams of Al2(SO4)3 can be produced from 10.0g of CuSO4?

32. bio

How Does exponential growth affects the 5 scientific principles of sustainability,reliance of solar energy,biodiversity,population control and nutrient recycling

33. chemistry

At a given temperature, for a reversible reaction , if the concentration of reactants is doubled then the equilibrium costant will (a) be doubled (b) be halved (c) change to 1/3 (d) remaine same

34. physics

Ball 1 is moving to the right at speed Vo when it collides with ball 2 - is initially at rest. After the collision, ball 1 's initial KE decreases by 80% and has a velocity at an angle of 40 degress below the horizontal. what fraction of the initial KE

35. Math

What is smallest 3 digit number using 1,0,6,2,9,7, with digits repeated and without digits repeated?

36. Math

The sum of the numerator and denominator of a fraction is 3 less than twice the denomiator.If the numerator and denomiator are decreased by 1,the numerator becomes half the denominator. Determine the fraction

37. maths

A woman is three times as old as her son just in 12years to came the woman will be twice as old as the son how old is the woman now?

38. Chemistry

Which one of these properties is directly proportional to molality and why? A) Electrical conductance B) Heat of solution C) Equilibrium of solution D) Vapour pressure Thanks

39. geometry

find the focus of x^2+4y^2+2x+24y++28=0. Thank you

40. History

How does the Supreme court affect the rights of citizens? *They affect citizens by looking into judical law before correcting political circumstances. Is my answer okay or should I fix it? Can you help me? I'm not 100% sure. Thank you :)

41. kyc

in a 2 digit number sum of two digit is 7 of the difference of two digit number and number obtained by reversing the degit is 9 find the numbers

42. English

1. Let's get out of here. 2. Let's go out of here. ------------------------------- Do you use only #1? What about #2? Why is #1 used frequently?

43. Math

Which is the largest 6 digit odd number without the repitition of the digits

44. Anonymous

what is 8 divided by 100