Wednesday

February 22, 2017
Total # Posts: 32

**math**

(a) RSTU is a cyclic quadrilateral in a circle of centre O.If RUT is 40°, what are the two values of <ROT (convex and concave)? (b) A RHC has a triangular catchment’s area PQR such that PQ = 22.1Km; PR = 13.5Km and <RPQ =56°. Find <PRQ.

*September 8, 2016*

**math**

(a) Simplify the following: (i) i345 (ii) 32/(-5i) (iii) 6/(7-8i) (iv) 9/(-8+7i) (b) Find the nature of the stationary points on the curve y = 4x3 – 3x2 – 6x + 2

*September 8, 2016*

**math**

(a) If K(−3, − x) and L(3,−4) are such that KL is perpendicular to MN with M(− 5, −6) and N(−3,− 5), find the value of x. (b) The curve y = ax2 + bx + c passes through the points (0, 2) and (1, 3) and its gradient where x = 1 is 6. ...

*September 8, 2016*

**math**

(a) A circle has centre at (−2,−1). One point on its circumference is (−2, −3). Find its radius, correct to 1d.p. (b) If y = x2 for 0 £ x £ 2 is completely rotated round the x – axis, find the volume of the solid of revolution produced.

*September 8, 2016*

**math**

(a) Integrate wrt x:(〖2x〗^4- x^2+2)/x^2 (b) The gradient of the tangent at a point on a curve is given by x2 + 2x – 2. Find the equation of the curve if it passes through (2,3).

*September 8, 2016*

**math**

(a) Find the resultant of the following coplanar forces acting at point O: 44N in direction 54°, 77N in direction 90°, 60N in direction 146°, 88N in direction 245°. Directions are measured anticlockwise from the positive x-axis. (b) If y = (x2 – 2x + 5)(3x...

*September 8, 2016*

**math**

The position vectors of P, Q and R are 2a – b, m(a – b), and a + b respectively. (a) Find the value of m if PQR is a straight line. (b) State the ratio PQ:QR.

*September 8, 2016*

**math**

) A chord AB of length 13cm is drawn in a circle centre O at a distance of 5cm from O. Find the radius of the circle. Stop at 1 d.p.(b) TA and TB are tangents to a circle centre O. TOC is a straight line and <ATB = 56°. Calculate <ACO.

*September 8, 2016*

**math**

) RSTU is a cyclic quadrilateral in a circle of centre O.If RUT is 40°, what are the two values of <ROT (convex and concave)? (b) A RHC has a triangular catchment’s area PQR such that PQ = 22.1Km; PR = 13.5Km and <RPQ =56°. Find <PRQ.

*September 8, 2016*

**chemistry**

The voltage of an electrochemical cell depends on the redox reaction occurring in the cell. Given a redox reaction below: Zn(s) + Pb2+(aq) --> Zn2+(aq) + Pb(s) Pb2+(aq) + 2 e--->Pb(s)Eº = -0.13V Zn2+(aq) + 2 e--->Zn(s)Eº = -0.76V Calculate the E.M.F (Voltage...

*March 9, 2016*

**c**

The voltage of an electrochemical cell depends on the redox reaction occurring in the cell. Given a redox reaction below: Zn(s) + Pb2+(aq) --> Zn2+(aq) + Pb(s) Pb2+(aq) + 2 e--->Pb(s)Eº = -0.13V Zn2+(aq) + 2 e--->Zn(s)Eº = -0.76V Calculate the E.M.F (...

*March 9, 2016*

**chemistry**

Given the equation below, if 3.87×1023 particles of Sb2S3(s) are reacted with excess Fe(s), what mass of FeS(s) is produced? Sb2S3(s) + 3Fe(s)→2Sb(s) +3FeS(s)

*March 9, 2016*

**chemistry**

Given the following Unknown atoms with their respective atomic numbers, X; Atomic number 19, Y; Atomic number 15, a. Deduce the identities of the elements X and Y. b. What are the mass numbers of the two elements X and Y? c. Calculate the number of Neutrons in the respective ...

*March 9, 2016*

**chemistry**

Given the equation below, if 3.87×1023 particles of Sb2S3(s) are reacted with excess Fe(s), what mass of FeS(s) is produced? Sb2S3(s) + 3Fe(s)→2Sb(s) +3FeS(s)

*March 9, 2016*

**chemistry**

6. Given the equation below, how many moles of each reactant were there if 13.7 moles of N2(g) is produced? 4NH3(g) + 6NO(g)→5N2(g) + 6H2O(g)

*March 9, 2016*

**chemistry**

3. For the reaction between Cu and Sn the potentials are given below; Cu2+(aq) +2e- -----------> Cu(s) Eºcathode = 0.34 (half-cell potential) Sn(s) -----------> Sn2+(aq) + 2 e- Eºanode = - 0.14 (half-cell potential) Calculate the E.M.F (Voltage) of the cell ...

*March 9, 2016*

**chemistry**

3. For the reaction between Cu and Sn the potentials are given below; Cu2+(aq) +2e- -----------> Cu(s) Eºcathode = 0.34 (half-cell potential) Sn(s) -----------> Sn2+(aq) + 2 e- Eºanode = - 0.14 (half-cell potential)

*March 9, 2016*

**chemistry**

2. The voltage of an electrochemical cell depends on the redox reaction occurring in the cell. Given a redox reaction below: Zn(s) + Pb2+(aq) --> Zn2+(aq) + Pb(s) Pb2+(aq) + 2 e--->Pb(s)Eº = -0.13V Zn2+(aq) + 2 e--->Zn(s)Eº = -0.76V Calculate the E.M.F (...

*March 9, 2016*

**chemistry**

1. Given that 50 grams of ice is heated at -20.0 °C to steam at 135.0 °C. i. Show the graph of the changes from ice to steam ii. Calculate the energy needed to change the ice to steam Please use these values: Heat of fusion = 334.16 J g¯1 Heat of vaporization = ...

*March 9, 2016*

**chemistry**

1. Given that 50 grams of ice is heated at -20.0 °C to steam at 135.0 °C. i. Show the graph of the changes from ice to steam ii. Calculate the energy needed to change the ice to steam Please use these values: Heat of fusion = 334.16 J g¯1 Heat of vaporization = ...

*March 4, 2016*

**math**

simplify 2xcubed+3x+5 divided by x+1. i am finding 2x squared-3x-5 and the book says 2xsquared-2x+5.please help am stuck

*April 7, 2013*

**History**

If u were a immigrant in America at 1880 its most likely u were a- german N Lutheran b Italin N Catholic C Irish N protestant Or D Swedish n protestant

*April 5, 2013*

**chemistry**

use the following data to calculate the mean bond enthalpy values for the C-H and C-C bonds. CH4(g)-C(g) + 4H(g) standard enthalpy change is +1648 kj/mol C2H6(g)-2C(g) + 6H(g) standard enthalpy change is +2820 kj/mol

*February 22, 2013*

**chemistry**

thank you

*January 26, 2013*

**chemistry**

What volume of 0.010M silver nitrate will exactly react with 20ml of 0.0080M socium chloride solution?

*January 26, 2013*

**chemistry**

a sample of compound C,H,N and O with a mass of 0.6216 was found to contain 0.1735g C,0.01455g H,0.2024g N.Its molecular mass 129.calculate its epirical and molecular formulas.

*January 25, 2013*

**chemistry**

an iron supplement is used to treat anaemia and 50mg of iron 2 is required per tablet.if the iron compound used in the tablet is FeSO4.7H2O,what mass of this compound would be required per tablet to provide the desired amount of iron 2?

*January 25, 2013*

**math**

i nee help

*January 7, 2013*

**Lotto 5/90 maths**

No ideal

*April 11, 2011*

**Math**

40.43

*November 1, 2009*

**Chemistry-Science**

I know that the edge for the first one is 2r so in terms of r the lattice point (pt) would = 16. To find the face diagonal using the Pythagorean theorem it would be (2r)^2+(2r)^2= (face diagonal)^2.. But every time I would plug it in, its incorrect. And for the body diagonal, ...

*February 14, 2009*

**Chemistry-Science**

Answer the following for a primitive cubic unit cell. Answers should be numerical, set r = 8.0 -edge in terms of r, the lattice pt radius:___ -face diagonal in terms of r, the lattice pt radius:___ -body diagonal in terms of r, the lattice pt radius:___ Answer the following ...

*February 14, 2009*

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