Search our library of homework questions

Top answers

All subjects

All levels

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

Answered by Paula S. • Chemistry tutor

69478 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 differentia...

Answered by Patrick K. • Maths tutor

6158 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 numorato...

Answered by George D. • Maths tutor

6756 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 i...

Answered by Dilyana K. • Physics tutor

3471 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, + infin...

Answered by Dilyana K. • Maths tutor

8823 Views