A 35.0 g piece of aluminum at 405^circ C was placed into a sample of water at 23.0^circ C . The final temperature of the water and aluminum was 55.0^circ C What is the heat change for the aluminum? c_(Al)=0.921(J)/(gcdot ^circ )C q_(Al)=[?]J Round your answer to three significant figures.

Convert 89000 g $Pb(NO_{3})_{2}$ to atoms

Given the following reactions and corresponding $\Delta H$ values, find the $\Delta H$ (to the nearest whole \#) for the reaction: $H_{2}SO_{4}(l)\rightarrow SO_{3}(g)+H_{2}O(g)$ $H_{2}S(g)+2O_{2}(g)\rightarrow H_{2}SO_{4}(l)$ $\Delta H=-235kJ$ $H_{2}S(g)+2O_{2}(g)\rightarrow SO_{3}(g)+H_{2}O(l)$ $\Delta H=-207kJ$ $H_{2}O(l)\rightarrow H_{2}O(g)$ $\Delta H=44kJ$ $\square $

Convert $4.68\times 10^{25}$ atoms $PBr_{3}$ to mol

Which of the following best describes a mixture? a material that is made up of many molecules a substance that can be changed into another substance a material that contains two or more substances a substance that has been broken down into Its smallest parts

What is used to of a hope of sixes in a a compound heard on the chermal reme? the periodic table prefixes chemical symbols the IUP AC

40. Using the hyphen form of symbol writing write the name of this atom. ${}_{9}^{19}F^{-1}$

Which of the following will not increase 1 point the rate of a chemical reaction? increasing surface area stirring decreasing the temperature increasing the concentration A __ is a substance that increases the rate of a reaction without being consumed. __ 1 point A(n) __ slows down the rate of a reaction. __ is a substance that 1 point

Use molecular orbital theory to determine the bond order in $H_{2}$ o 2 1 3

What is enthalpy? the heat absorbed or released during a phase change the heat content.of a system at constant pressure the heat absorbed during an endothermic reaction the heat given off during an exothermic reaction

1. What are two ways in which real gases differ from ideal gases? $\square $