Jika Kb NH4OH=1,8x10^-5 maka besarnya NH4Br(Mr=98) yang harus dilarutkan dalam 500 mL larutan untuk mendapatkan larutan dengan pH=5-log2 adalah..
a.0,36 gram
b.0,72 gram
c.3,53 gram
d.35,3 gram
e.353 gram
a.0,36 gram
b.0,72 gram
c.3,53 gram
d.35,3 gram
e.353 gram
fatihahalhusna
![\displaystyle pH=5-\log2\\{[H^+]}=2\times10^{-5}\ M\\\\{[H^+]}=\sqrt{\frac{K_w\times M}{K_b}}\\\\2\times10^{-5}=\sqrt{\frac{10^{-14}\times M}{1,8\times10^{-5}}}~~~(\text{Kuadratkan}\\\\4\times10^{-10}=\frac{10^{-9}M}{1,8}\\\\M=0,72\ M](https://tex.z-dn.net/?f=%5Cdisplaystyle+pH%3D5-%5Clog2%5C%5C%7B%5BH%5E%2B%5D%7D%3D2%5Ctimes10%5E%7B-5%7D%5C+M%5C%5C%5C%5C%7B%5BH%5E%2B%5D%7D%3D%5Csqrt%7B%5Cfrac%7BK_w%5Ctimes+M%7D%7BK_b%7D%7D%5C%5C%5C%5C2%5Ctimes10%5E%7B-5%7D%3D%5Csqrt%7B%5Cfrac%7B10%5E%7B-14%7D%5Ctimes+M%7D%7B1%2C8%5Ctimes10%5E%7B-5%7D%7D%7D%7E%7E%7E%28%5Ctext%7BKuadratkan%7D%5C%5C%5C%5C4%5Ctimes10%5E%7B-10%7D%3D%5Cfrac%7B10%5E%7B-9%7DM%7D%7B1%2C8%7D%5C%5C%5C%5CM%3D0%2C72%5C+M "\displaystyle pH=5-\log2\\{[H^+]}=2\times10^{-5}\ M\\\\{[H^+]}=\sqrt{\frac{K_w\times M}{K_b}}\\\\2\times10^{-5}=\sqrt{\frac{10^{-14}\times M}{1,8\times10^{-5}}}~~~(\text{Kuadratkan}\\\\4\times10^{-10}=\frac{10^{-9}M}{1,8}\\\\M=0,72\ M")
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