# unit

1. ### Chemistry unit lab problem

Hi everyone, Wondering if someone could help me with this lab problem. I can't get my head around it. NaOH= 40,00g/mol p = 2,10 g/cm3 I want 100 ml aq with 0,400 mol/kg How do I solve this? Thanks in advance:)
2. ### Calculate volume of HCl needed to change buffer pH by 1 unit???

How do you calculate the amount of HCl needed to change the pH of a NH3/NH4+ buffer by 1 unit? There was 100mL of NH3 2M and 10.698g of NH4 0.5M and then this was mixed with 400mL of water to make 500mL buffer solution. Only 80mL of this was used for each trial. HCl was 1M. Starting pH was...
3. ### Unit Conversion

The problem states: Express an accelration of 9.81 meters · second^2 in kilometers per hour squared. So far I have come up with: 9.81 m · s^2 x 1 km / 10^3 m x (3600 s/ 1h)^2 It's been a long time since I've done this sort of thing and for some reason I cannot for the life of me figure...
4. ### Unit Comversion/Dimensional Analysis Question:

Hello! I am returning to college for a second B.S. after graduating college over a decade ago, and now I'm taking an inorganic chem prerequisite. I know this is a very basic problem, but I think I'm not clearly understanding either a sig fig or rounding rule here. I must state that I didn't...
5. ### Unit cell packing efficiency and density

Here's the question: You are on the Starship Enterprise and come across a planet that hasn’t been visited before. As the science officer, you go down to the planet surface and you find a very interesting “rock” that actually is a pure element. Determining, from X-ray diffraction studies, that...