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  1. M

    Identifying anions and cations

    Need help here! Assess the effectiveness of identifying anions and cations through precipitation reaction. Thanks in advanced! :)
  2. M

    Validity and reliability of secondary sources

    Ohhh that just makes it so much easier to answer these questions. Thanks a lot! However I don't know if that would be enough to gain 4marks for a, and 3marks for b
  3. M

    Validity and reliability of secondary sources

    I'm having trouble answering these questions... Please help a) identify data sources and evaluate the validity of the secondary info in relation to your chosen non-infectious disease b) assess the reliability of your secondary info and the data that you have obtained in the relation to...
  4. M

    Smoking and cancer questions

    Need help with a question... a) draw a graph (don't need help with this...) b) compare the death rate for smokers and non-smokers in each category. On the basis of the data in figure, what conclusions can be drawn about the effect of smoking in: i) smokers and non-smokers of...
  5. M

    Nuclear chemistry question

    I don't know how to do this question, please tell me what to do Plutonium has a half life of 2.4 x 10^4 years. How long would we need to store a sample of plutonium for its activity to drop to less that 0.1% of its original value? Thanks in advance! :)
  6. M

    Quad polynomials help

    I need help with these questions 1) find values of m such that mx^2 + 3x -4 <0 for all x 2) solve 5^2x - 26.5^x +25=0 Thanks in advance
  7. M

    Preparing an ester - adding excess??

    Ohh makes sense, thanks :)
  8. M

    Preparing an ester - adding excess??

    I prepared an ester with 1-pentanol and ethanoic acid. So I have this question... I know excess acid was added but "why was an excess of that reagent used rather than an excess of the other one? (Densities of 1-pentanol and glacial acid are 0.81 and 1.04g/ml respectively)" What has the density...
  9. M

    Polymers help!

    I don't really know which changes, it was a question from a textbook... Maybe it's the change in structure
  10. M

    Polymers help!

    I need to know, "how changing a monomer affects the properties of the polymer produced" Thanks in advance :)
  11. M

    Help with calculations

    Yeah I know how to do that... Need part b
  12. M

    Help with calculations

    I need help with this question: In an experiment, a student added 20.00ml of 0.09mol/L of nitric acid to 25.00ml of 0.11mol/L potassium hydroxide. a) determine which substance is in excess b) calculate the vol of 0.1mol/L KOH or HNO3 needed to neutralize the remaining solution I can do...
  13. M

    Alkanes and alkenes help

    I need to know how the following compounds can be prepared: a) 2-butanol b) 2,3-dichloropentane c) 3-bromohexane Thanks in advance :)
  14. M

    Help with assessment task

    I haven't gone into much detail for blade runner in school yet... But I can think of some similarities between the two. For example: they're both about creating life through science, however one is set in the future and the other in the past, and the created being both pursue their creator to...
  15. M

    Help with assessment task

    I need to create a visual representation, for Frankenstein and Blade Runner, of the elective Text in Time (comparing the treatment of similar content in a pair of texts composed in different times and contexts may reflect changing values and perspectives). I have to provide and oral presentation...
  16. M

    Roots and coefficients of polynomials

    I need help with this question... I can't seem to get it right :( Two roots of x^3+mx^2+15x-7=0 are equal and rational. Find m. Thanks in advance!
  17. M

    Polynomials question help!

    No it's just p(a) = p'(a) = 0
  18. M

    Polynomials question help!

    I already found part a and having trouble with part b of this question, please help. a) the polynomial equation p(x)=0 has a triple root at x=a. By writing p(x)=(x-a)^3.Q(x), show that p(a)=p'(a)=0. b) hence find values of u and v if x^5 -9x^4 +ux^3 -18x^2 +v +27 =0 has a triple root at x=3...
  19. M

    Help with parametric question!

    Thanks it's really helped :)
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