In determining the percentage purity of an impure NaCo3 for 4.2g of the impure was place in measuring cylinder to work up to 1000cm . the resultant solution is neutralize by 0.092m of 20.40cm3 Hcl in lab [ na=23,o= 16, c=12, h=1, cl=35-5] hint: percentage purity =mass pure substance ×100
mass concentrate : impure substance??

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)

Debbie places two shopping carts in a cart corral she pushes the first cart which then pushes a second cart what force is being exerted

Which of the following is the phase that results when the moon is on the opposite side of the earth from the sun? a. quarter moon b. crescent moon c. new moon d. full moon