Chemistry

posted by .

In an exothermic reaction, is the heat of the reation less than, greater than, or equal to zero?

In an endothermic reaction, is the heat of reaction less than, greater than, or equal to zero?

  • Chemistry -

    Exothermic reaction - Energy is released - so it is less than zero. [Negative value]

    Endothermic reaction - Energy is absorbed - greater than zero [Positive value]

    Examples -

    Exothermic Reactions
    C(s) + O2(g) → CO2(g); ΔH = –393.5 kJ
    H2(g) + 1/2 O2(g) → H2O(l); ΔH = –285.8 kJ

    Endothermic Reactions
    N2(g) + O2(g) → 2NO(g); ΔH = +180.5 kJ > 0
    C(s) + 2S(s) → CS2(l); ΔH = +92.0 kJ > 0

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    for the reaction 4NH3(g) + 5O2(g) <--> 4NO(g) + 6H2O(g) if H = -950kJmol-1, does that mean it's an exothermic reaction?
  2. College Chem

    4. Write the balanced equation for CH4+Cl2„_CH2Cl2+HCl6. For the reaction in problem 4, Heat of Reaction = -118.3 kcal/mol. Identify whether this is an exothermic or endothermic reaction. Calculate the Heat of Reaction when 6.00 …
  3. chemistry.

    The thermodynamic equilibrium constant for the following reaction is 0.15 at 1227°C. 2 SO2(g) + O2(g) 2 SO3(g) Which is true?
  4. CHEm. help please

    The thermodynamic equilibrium constant for the following reaction is 0.15 at 1227°C. 2 SO2(g) + O2(g) 2 SO3(g) Which is true?
  5. Rational Inequality with Absolute Value

    Here's a question I'm having trouble with: |x|/|x+2|<2 Solve for x. I'm trying to use the case method to solve this problem. Basically I just need confirmation that I did this correctly. I'm doing this through distance learning …
  6. Chemistry

    True or false 1. The energy of a collision between atoms or molecules must be greater than the activation energy for bonds to be broken?
  7. chemistry

    consider the following changes at constant temperature & pressure H2O(s) --yields-- H20(l); Delta H1 H2O(l) --yields-- H2O(g); Delta H2 H2O(g) --yields-- H2O(s); Delta H3 Using Hess's law, the sum of the deltas is a. equal to 0 b. …
  8. math

    State the null hypothesis, Ho, and the alternative hypothesis, Ha, that would be used to test the following statements. (a) The linear correlation coefficient is positive. Ho: ñ ---Select--- not equal to equal to greater than less …
  9. Chemistry

    The free energy profile as the reaction goes from reactants to products is a straight diagonal line from 50 kj/mol to 80 kj/mol. Is the reaction exothermic or endothermic?
  10. chemistry

    3HgO→2Hg+O2 Which of the following can definitely be concluded from the equation and heat of reaction above?

More Similar Questions