The element X is titanium.
According to the question, the percentage by mass of Cl in XCl4 is 75.0%.
The percentage by mass is obtained from;
Mass of element in the compound/molar mass of compound * 100
Hence;
Let the mass of the unknown element be X
75 = 142/X + 142 * 100
75 (X + 142) = 142 * 100
75X + 10650 = 14200
75X = 14200 - 10650
X = 14200 - 10650/75
X = 47
Hence, X is titanium.
Learn more; brainly.com/question/1363167
Answer:
the product is Mg(Clo3)2 + AgI
When 0.34 of HNO₃ is titrated to equivalence using 0.14 l of 0.1 m NaOH then the concentration of HNO₃ is 0.041 M
The reaction of neutralization of HNO₃ with NaOH is
HNO₃ + NaOH → H₂O + NaNo₃
When 1 mole of HNO₃ react with 1 mole of NaOH, based on chemical rection the moles of NaOH at equivalence point are equal to moles of HNO₃ present in solution: -
With the mole and volumes, we can find molarity as follows:
Moles of NaOH = moles HNO₃
⁼ 0.14 L X (0.1 mol NaOH/L) = 0.014 mole NaOH
=0.014 mol HNO₃
Molarity: -

= 0.041 M
Thus, from above solution we concluded that the concentration of HNO₃ solution is 0.041 M.
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Answer: (D.) Planting Roof gardens
Explanation: I'm really hoping you get this right but the reason of my answer is because Trees, green roofs, and vegetation can help reduce urban heat island effects by shading building surfaces, deflecting radiation from the sun, and releasing moisture into the atmosphere.