Identify each of these reactions as endothermic or exothermic: a) heat + H2O(l)  –> H2O    b) H2O(g)  –> H2O(l) + heat c) K2CO3(s) –> K2CO3(aq) + heat d) heat+ NH4Cl(s) –> NH4Cl(aq)  

A chemist carries out this reaction in the laboratory, using grams of zinc and an excess of sulfur:  She isolated g of ZnS. Zn + S –> ZnS   Using the balanced equation, calculate the percent yield the chemist retrieved from the reaction.   What is her percent yield for this reaction?   percent yield= (actual yield)/(theo yield) *100%

The empirical formula for aluminum oxide is ___.  Make sure to leave no spaces.

In this reaction, the excess reagent is ___. 2Al + 5Br2  –> 2AlBr3   +  2Br2  

A chemist conducts a calorimetry experiment on an unknown metal. The mass of the metal is 24.4 g. The chemist heats the metal to 100 °C, then places it in a coffee-cup calorimeter containing 108.5 g of water.  The temperature of the water rises from 21.3 to 25.0 °C.   Useful equations: Cm= [mwCw(

When heated, zinc and sulfur combine to form a new compound, zinc sulfide, ZnS.  In this reaction, 

Which of the following statements is LEAST true about sexual socialization in the home?

How does colorism affect women in the United States?

Which of the following is the BEST explanation as to why wearing a leotard, which is a skin-tight one-piece garment, might interfere with a woman’s ability to complete cognitive or behavioral tasks, such as taking a math test or giving an oral presentation?

According to the text, compared to less attractive women, attractive women may