Posts by chemdummy

Total # Posts: 18

  1. chem

    What relationship exists between H^+ ion concentration and OH^- ion concentration? Waht is the OH^- concentration of an aqueous solution with the H^+ concentration of 10^-4M. Calculate the pOH? Need help with this pls. thank you.
  2. chem

    On the average; glucose (C6H1206) makes up about 0.100% by weight of human blood. How much glucose is there in 1.00 kg of blood?
  3. chem

    how to prepare 300ml of .250M HCl from a 1.00 M HCl stock solution
  4. chem

    You have a large amount of 7.50M stock solution. You need 1.80L of 3.00M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?
  5. chem

    A very flexible helium-filled balloon is released from the ground into the air at 20degree C The initial volume of the balloon is 5.00L , and the pressure is 760mmHg. . The balloon ascends to an altitude of 20Km , where the pressure is 76.0mmHg and the temperature is -50degree...
  6. chem

    sorry but it should be -50 degree C i typed it wrong
  7. chem

    A very flexible helium-filled balloon is released from the ground into the air at 20degree C The initial volume of the balloon is 5.00L , and the pressure is 760mmHg. . The balloon ascends to an altitude of 20Km , where the pressure is 76.0mmHg and the temperature is 50degree ...
  8. chem

    Is CaCl2 an ionic compound or molecule? plss help. i'm just a little bit confused.
  9. chem

    Why is ther no such thing as NaCl molecule? pllllsss neeed heeelp thank you
  10. chem

    How many atoms are there in the following problems? which one has the most number of atoms? a. 5 molecuels (NH4)2S b. 9 molecules H2O2 c. 11 molecules O3
  11. chemistry

    How many moles of water are there in 5 moles of Tungsten(V)oxalate tetrahydrate?
  12. chemistry

    What is the mass of 4.80 moles of MgCl2?My answer is: Mg=24.3 g/mole Cl2=35.5g/mole*2=71g/mole so, Mg 24.3+ Cl2 71= 95.3g/mole therefore 4.80 moles * 95.3 g/mole=471.84g Am i right pls correct me if i'm wrong thanks
  13. chemistry

    thanks DrBob222 for the answer kindly teach me what does sum coefficient mean and how to get it based from this problem
  14. chemistry

    complete and balance Co(OH)3(aq)+Na2CO3(aq)
  15. Chemistry

    what is the 1. chemical equation 2. complete ionic equation 3. net ionic equation include phase of HCH3COO+NaHCO3 pls correct my answers 1. CH3COOH(aq)+NaHCO3(aq)+CH3COONa(aq)+H2O(l)+CO2(g) 2. CH3COOH(aq)+OH-(aq)=CH3COO-(aq)+H2O(l) 3. OH(aq)+CO2(g)
  16. chemistry

    C4 H10 O or diethyl ether or with a formula of CH3CH2OCH2CH3 its stick structure is H H H H ! ! ! ! .. H-C-C-C-C- O-H ! ! ! ! .. H H H H I used the this ! sign as a sign for bond. pls help me to determine the geometry for each central atom in this structure. 1) C Trigonal 2) C...
  17. chemistry

    colorless vinegar added to purple cabbage juice turns pink What is the reason behind and why is it considered a chemical change?
  18. chemistry

    When two solutions are mixed and a new color is observed, is this color change an indication that a chemical reaction has occurred? Explain. It is not possible to directly observe chemical bonds breaking and forming during a reaction, molecules and atoms are way too small. ...