Learn more about our help with Assignments: Chemistry
Search & Filtering
3. Which salt has a higher % by mass of chlorine, NaCl or CaCl2? Which has the greater molar mass?
4. When NaCl is dissolved in water it gets colder. When CaCl2 dissolves in water it gets warmer.
a. Identify which change is endothermic and which is exothermic.
b. What would be the sign on DH for each change?
c. To which side of the chemical equation would the heat term go in each case?
5. You are asked to determine the solubility of a NaCl solution. To do this, you make a saturated solution of the salt. Then you filter out the excess solid and measure out 10.0 mL of the filtrate into an evaporating dish. This sample is then completely. When cool, it was determined that 3.5 g of salt was in the evaporated sample.
a. What is the solubility of NaCl in terms of grams solute/grams H2O? Why is a saturated solution needed to determine the solubility?
b. Would you expect more or less salt to dissolve if the temperature of the water is doubled? Why?
c. For each step in the procedure, identify the equipment needed.
d. Explain, in detail, how the mass of the dissolved salt was determined (what masses needed to be recorded during the experiment?).
e. Identify the proper safety precautions for this procedure
4. When NaCl is dissolved in water it gets colder. When CaCl2 dissolves in water it gets warmer.
a. Identify which change is endothermic and which is exothermic.
b. What would be the sign on DH for each change?
c. To which side of the chemical equation would the heat term go in each case?
5. You are asked to determine the solubility of a NaCl solution. To do this, you make a saturated solution of the salt. Then you filter out the excess solid and measure out 10.0 mL of the filtrate into an evaporating dish. This sample is then completely. When cool, it was determined that 3.5 g of salt was in the evaporated sample.
a. What is the solubility of NaCl in terms of grams solute/grams H2O? Why is a saturated solution needed to determine the solubility?
b. Would you expect more or less salt to dissolve if the temperature of the water is doubled? Why?
c. For each step in the procedure, identify the equipment needed.
d. Explain, in detail, how the mass of the dissolved salt was determined (what masses needed to be recorded during the experiment?).
e. Identify the proper safety precautions for this procedure
1.2380 g sample composed of lead, dithoionate and water, of unknown proportions[Pb(S2O6)n.mH2O] is analysed to determine the proportions. It is heated in a crucible and on loss of water, the mass is reduced to 1.0331g. The remaining lead dithionate is taken up in solution, processed and percipitate as PbS. 680.4mg of PbS was obtained gravimetrically. From the given information, determine the unknown n and m in the molecular formula for the compound.
I am a jeweller and have found an old recipe for frosting gold (making the gold a richer more yellow colour) and I wanted to ask how stable it is. It is 119ml (4oz)of sulphuric acid, 59 grams (2oz) of potassium nitrate and 7.4 grams (1/4oz) of salt. I just wanted to know if this formula is stable? I need to quench hot metal in it.
i have one ? to you
Fe+2 + Ce+4 ---> Fe+3 + Ce+3
in this reaction
why in equivalence point [Fe+2]=[Ce+4]
but in equivalence point there is no any reactant
?
Fe+2 + Ce+4 ---> Fe+3 + Ce+3
in this reaction
why in equivalence point [Fe+2]=[Ce+4]
but in equivalence point there is no any reactant
?
Hi,
I have a few questions about two substances, toluene and acetone. I wish to soak a chunk of floral foam (Oasis - used for flower arranging) which is made of a phenolic resin. This foam is usually soaked with water and I am currently using it to model a drying process in my research. What I would like to know is, if I was to soak this foam with liquid toluene or acetone, instead of water, would the foam simply dissolve in either of these two liquids or do you think the foam would still hold it like it does with the water? And do you know which substance, toluene or acetone would be better suited for this?
In case you are wondering, I am interested in these to properties because they are used as tracers in a certain type of laser-imaging technique I am interested in.
If you could answer these questions for me, I would be hugely grateful.
Kind regards
I have a few questions about two substances, toluene and acetone. I wish to soak a chunk of floral foam (Oasis - used for flower arranging) which is made of a phenolic resin. This foam is usually soaked with water and I am currently using it to model a drying process in my research. What I would like to know is, if I was to soak this foam with liquid toluene or acetone, instead of water, would the foam simply dissolve in either of these two liquids or do you think the foam would still hold it like it does with the water? And do you know which substance, toluene or acetone would be better suited for this?
In case you are wondering, I am interested in these to properties because they are used as tracers in a certain type of laser-imaging technique I am interested in.
If you could answer these questions for me, I would be hugely grateful.
Kind regards
How many grams of methane gas (CH4) are in a 15.8 liter sample at 1.2 atmospheres and 27°C?
What is the volume of 3.5 moles of oxygen gas (O2) at standard temperature and pressure (STP)?
An iceberg has a volume of 8975 ft^3. What is the mass in kilograms of the iceberg?
1. an aqueous solution has a pH equal to 2.what do you infer about its acidic and basic character?
2.what is the colour of methylorange i.acidic mediumii.basic medium
2.what is the colour of methylorange i.acidic mediumii.basic medium
Hi,
I just want to ask for safety purpose
1. what will happen if lye+vineger were mix together?
2. what will happen if lye+water+vineger were mix together?
3. what will happen if lye+water+oil+vineger were mix together?
4. I want to make sure what will happen will this explode or something?
I'm a soap maker, I'm mixing lye+water+oils to make a soap. the ph is 7
5. how can you lower a ph level of a soap to ph5.5 or ph5?
6. is the vinegar should be added?
I just want to ask for safety purpose
1. what will happen if lye+vineger were mix together?
2. what will happen if lye+water+vineger were mix together?
3. what will happen if lye+water+oil+vineger were mix together?
4. I want to make sure what will happen will this explode or something?
I'm a soap maker, I'm mixing lye+water+oils to make a soap. the ph is 7
5. how can you lower a ph level of a soap to ph5.5 or ph5?
6. is the vinegar should be added?
"assignmentexpert.com" is professional group of people in Math subjects! They did assignments in very high level of mathematical modelling in the best quality. Thanks a lot
#339914 on Dec 2023
#339914 on Dec 2023