Answer: 0.87 g of an 8% w/w progesterone gel must be mixed with 1.45 g of a 4% w/w progesterone gel to prepare a 5.5% w/w gel.
Explanation:
According to the dilution law,
where,
= concentration of ist progesterone gel = 8%w/w
= weight of ist progesterone gel = x g
= concentration of another progesterone gel = 4% w/w
= weight of another progesterone gel = 1.45 g
= concentration of resulting progesterone gel = 5.5%w/w
= weight of resulting progesterone gel = (x+1.45) g
Thus 0.87 g of an 8% w/w progesterone gel must be mixed with 1.45 g of a 4% w/w progesterone gel to prepare a 5.5% w/w gel.
Answer:
0.04 M is the lowest concentration of chloride ions that would be needed to begin precipitation.
Explanation:
Concentration of lead nitarte = ![[Pb(NO_3)_2]=0.010 M](https://tex.z-dn.net/?f=%5BPb%28NO_3%29_2%5D%3D0.010%20M)
1 Mole of lead nirate gives 1 mole of lead ion.
Concentration of lead ion in the solution = 
Concentration of chloride ions = ![[Cl^-]](https://tex.z-dn.net/?f=%5BCl%5E-%5D)
The value of ![K_{sp} for [tex]PbCl_2= 1.6\times 10^{-5}](https://tex.z-dn.net/?f=K_%7Bsp%7D%20for%20%5Btex%5DPbCl_2%3D%201.6%5Ctimes%2010%5E%7B-5%7D)
![K_{sp}=[Pb^{2+}][Cl^{-}]^2](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BPb%5E%7B2%2B%7D%5D%5BCl%5E%7B-%7D%5D%5E2)
![1.6\times 10^{-5}=0.010 M\times [Cl^{-}]^2](https://tex.z-dn.net/?f=1.6%5Ctimes%2010%5E%7B-5%7D%3D0.010%20M%5Ctimes%20%5BCl%5E%7B-%7D%5D%5E2)
![[Cl^-]=0.04 M](https://tex.z-dn.net/?f=%5BCl%5E-%5D%3D0.04%20M)
0.04 M is the lowest concentration of chloride ions that would be needed to begin precipitation.
About 1.051 moles (depends on how u round it)
Answer:
Explanation:
All you need to know is the atomic mass of platinum, and Avogadro's number.
2.00g Pt divided by atomic mass gives you the moles of platinum, and multiplying by avogadro's number (6.022 x 10^23) gives you the number of atoms.
Atomic mass of platinum can be found on any periodic table.
Hope this helped.
How about P-La-S-Ti-C W-Ra-P?
