Top answers

What mass of carbon dioxide is produced from burning 100 grams of ethanol in oxygen according to this reaction: C2H5OH + 3 O2 --> 2 CO2 + 3 H2O

Firstly, make sure the equation is correctly balanced – which it is here; comparing right sight with left: Left=Right i.e.: 2 carbon atoms, 6 hydrogen a, 7 oxygen a Next make it clear what is your unknown, s...
PS
Answered by Paula S. • Chemistry tutor
70633 Views

How do you integrate by parts?

To integrate the product of two functions - say f(x) = xsinx, the product of g(x) = x and h(x) = sin(x) - the we use integration by parts. Since integration is the inverse of differentiation, we'll appeal to...
PK
Answered by Patrick K. • Maths tutor
6768 Views

Given that (2x + 11 )/(2x + 1)(x + 3) ≡ A /(2x + 1) + B /(x + 3) , find the values of the constants A and B. Hence show that the integral from 0 to 2 (2x + 11)/ (2x + 1)(x + 3) dx = ln 15.

First starting from the right hand side. A /(2x + 1) + B /(x + 3) = A(x+3)+B(2x+1)/(x+3)(2x+1) Therefore the numerator = (A+2B)x+(3A+B) Equating this numorator with the Left hand side we are presented with t...
GD
Answered by George D. • Maths tutor
7326 Views

Two identical objects have a charge of magnitude q. If r is the distance bethween them, what should their mass be so that the objects are balanced.

Our first step in this physics problem should be to identify all of the forces that act on the objects. There are two forces here,electrical and gravitational. Since both objects have the same charge in magn...
DK
Answered by Dilyana K. • Physics tutor
3896 Views

Use the Intermidiate Value Theorem to prove that there is a positive number c such that c^2 = 2.

This exercise is asking to prove the existance of the square root of 2. So let's consider the function f(x) = x^2. Since f(x) is a polynomial, then it is continuous on the interval (- infinity, + infinity). ...
DK
Answered by Dilyana K. • Maths tutor
9607 Views