1.阿伏加德罗常数若以He原子的原子数目表示,则数值上与—gHe所含原子数目相同,若以氧原子的数目表示,则数值上与—g氧
1个回答

1:因为氧的相对质量是16,1除以16=1/16

2:20ml=20cm3 H2SO4质量=20*98%*1.84=36.064g,n=m/M=36.064/98=0.368mol

c=n/v=0.368mol/1L==0.368mol/L

3:2KMnO4+16HC1=2KCl+2MnCl2+5CL2+8H2o 设HCl体积为X,Cl质量m

316 584 355

15.8g 1.19*36.5%*X m

X=67.2268ml

HCl 质量=80g HCl(n)=m/M=21.9mol

m=17.75g Cl2(n)=n/M= 0.25mol

V=n*22.4L/mol= 5.6L

4:(1)因为是气体,n=V/22.4L/mol=224L/22.4L=10mol

m(HCl)=10mol*36.5g/mol=365g

m(H2O)=635ml*1g/ml=635g

V=m/密度=1000g/1.18g/cm^3=847.4576ml

c=n/v=10mol/847.4576ml/1000=11.8mol/L

n=cv=0.01L*11.8mol/L=0.118mol

c=n/v=0.118mol/1.45L=0.0813mol/L

(2)n=cv=0.04L*0.065mol/L=0.0026mol

m=n*M=0.0026mol*106g/mol=4.24g

Na2CO3+2HCL=2NaCL+H2O+CO2!

106 73

4.24g X

X=2.92g

m=n*M

n=c*v

m=c*v*M

2.92g=0.0813mol/L*v*73g/mol=0.492L

0.492L=492mol

终于做完了,列我最佳.再追加我点分吧,做了几十分钟的好累的