Answer Base

1) marble chips react with a dilute hcl acid solution. co2 released.investigate how particle size affects the speed at which the mass is lost from the reaction mixture as gas is released.2)clothes made from certain fabrics , e.g denim , are not suitable for hill walking or mountain climbing.carry out an investigation to compare the thermal insulating properties of three different fabrics when they are dry and wet.denim must be included as one of the three fabrics. thanks ^_^

I already answered 1 recently.here is my design for no. 2 created on the spur of the moment and not optimised by actually conducting this experiment a number of times.for no. 2, there are 6 sets of measuements, as well as time, to be considered. one or two assistants would help to speed things up. speed is important here, at certain phases of the experiment, otherwise you must do many more measurements and may have to use expensive apparatus to do this.get six identical glass bottles. prepare 6 samples of cloth all of the same size to wrap around a large proportion of each bottle. double, or triple thicknesses of each cloth sewed together might be needed. six thermometers would be nice.heat enough water to maybe 50 degrees centigrade. fill all 6 bottles and stick a thermometer in each. measure the intial temperature, and attach 3 wet cloths on three bottles and 3 dry cloths on the 3 other bottles. after about 2 hours measure the 6 temperatures again.record all results, naturally, and comment on them. the bottom line will be how much cooling occurred with the different materials wet and dry.