What is the percent by mass of chlorine CI in NaCI to 3 significat digits please help

What is the volume of the fluid in the graduated cylinder with accuracy and measured to the correct degree of precision? 41.2 ml 42.0 ml 41.23 ml 41.89 ml

What is the overall order of reaction for rate = k[no2]2 ? second order 3/2 order third order zero order none of the listed answers are correct

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size