Analysis of a compound indicates that it contians 1.04 g k, 0.70 g cr, and 0.86 g o. find its empirical formula. 1. k2cro3 2. kcro4 3. k2cro4 4. kcro3

Empirical formula of a chemical compound is the simplest positive integer ratio of atoms in the compound.
 The first step is getting the number of moles of each.
Potassium- 1.04/39 = 0.0267
Chromium-   0.7 /52 = 0.0135
Oxygen-  0.86/16 = 0.05375
 Then we divide each with the smallest number,
0.0267/0.0135= 1.98
0.0135/0.0135=1
0.05375/0.0135= 3.98
Therefore the ratio is 2:1:4
Hence the empirical formula is K2CrO4

The answer is solid copper 

Answer is:     molar solubility of  yttrium fluorid is 4.23·10⁻⁶ m. balanced chemical reaction: yf₃(s)  → y³⁺(aq) + 3f⁻(aq). ksp = 8.62·10⁻²¹. ksp = [y³⁺]  · [f⁻]³.[y³⁺] = [yf₃] = s.[f⁻] = 3[yf₃] = 3s.ksp(yf₃)  = s  · (3s)³.8.62·10⁻²¹ = 27s⁴.s(yf₃)  =  ⁴√(8.62·10⁻²¹  ÷ 27).s(yf₃)  = 0.00000423 m.s(yf₃) = 4.23·10⁻⁶ m.