I need to work out the density of the gaseous oxide of arsenic at STP in g L-1
I realise density = mass/volume but my answer works out very high!! I have already worked out the volume to be 52cm^3 (Cubed). the mass to start with was 0.702g and at the end of the reaction was 0.927g. I know this isn't difficult and my figures are wrong!!!
I have tried 0.927g/0.052g but get 18 L-1. So whether I use the difference in the mass I don't know, i.e. 0.225/0.052g gives 4.32g L-1
Does any of this make sense to anyone? This is annoying me so much and is worth only 2 marks...
From your statement, I have no idea what you are doing.
You need the mass of the oxide only, not the collection vessel. You need the volume of the gas.
density=mass/volume. If the mass is in grams, and the volume in cm cubed, then the density will be in g/cubic cm.
thanks Bob, sorry to confuse you, I confuse myself!!! I understand I only need the oxide.
No problem! Let's break it down step by step.
To calculate the density of the gaseous oxide of arsenic at STP, you need the mass of the oxide and the volume of the gas.
1. First, you mentioned that you have the initial mass of the oxide as 0.702g and the final mass after the reaction as 0.927g. To find the mass of the oxide, you need to subtract the initial mass from the final mass. In this case, the mass of the oxide would be 0.927g - 0.702g = 0.225g.
2. Next, you mentioned that you have calculated the volume of the gas to be 52cm³. To convert this volume to liters, divide by 1000 (since there are 1000 cm³ in 1 liter). So, the volume would be 52cm³ / 1000 = 0.052L.
3. Finally, to find the density of the gaseous oxide at STP, you can use the formula density = mass / volume. Plug in the values we calculated: density = 0.225g / 0.052L ≈ 4.327 g/L.
So, the density of the gaseous oxide of arsenic at STP would be approximately 4.327 g/L.
Remember to double-check your units and make sure they're consistent throughout the calculations.