The quantity of antimony in a sample can be determined by an oxidation–reduction titration with an oxidizing agent. a 6.47 g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated hcl ( aq ) and passed over a reducing agent so that all the antimony is in the form sb 3 ( aq ) . the sb 3 ( aq ) is completely oxidized by 33.4 ml of a 0.110 m aqueous solution of kbro 3 ( aq ) . the unbalanced equation for the reaction is bro − 3 ( aq ) sb 3 ( aq ) ⟶ br − ( aq ) sb 5 ( aq ) (unbalanced) calculate the amount of antimony in the sample and its percentage in the ore.

The law of conservation of energy states that energy cannot be created or , energy can be from one substance to another. the first blank is ' destroyed ' and for the second blank is ' transferred '

Clothing made of several thin layers of fabric with trapped air in between, often called ski clothing, is commonly used in cold climates because it is light, fashionable, and a very effective thermal insulator. so it is no surprise that such clothing has largely replaced thickand heavy old-fashioned coats. (a) consider a jacket made of five layers of 0.1-mm-thick synthetic fabric (k = 0.13 w/m·°c) with 1.5-mm-thick air space (k = 0.026 w/m·°c) between the layers. assuming the inner surface temperature of the jacket to be 28°c and the surface area to be 1.25 m2, determine the rate of heat loss through the jacket when the temperature of the outdoors is 0°c and the heat transfer coefficient at the outer surface is 25 w/m2·°c. (b) what would your response be if the jacket is made of a single layer of 0.5-mm-thick synthetic fabric? what should be the thickness of a wool fabric (k = 0.035 w/m·°c) if the person is to achieve the same level of thermal comfort wearing a thick wool coat instead of a five-layer ski jacket?

Could we see a galaxy that is 20 billion light-years away?