How many grams of urea a ((NH,),CO)m must be added to 489 g of water to give a solution with a vapor pressure 2.77 mmHg less than that of pure water at 30 °C? Round your answer to 3 significant digits. Note: Reference the Vapor pressure of water (H₂O) at selected temperatures table for additional information. (NH,),CO-| g X 18民政□ ■ 〗 ∞ olo A

Anhydrous CuSO4 is converted to CuSO4・xH2O to absorb water from certain liquids. What is the value of x if 24.3 g of anhydrous CuSO4 is required to remove 13.7 g of H2O from a gallon of gasoline?  Relative atomic masses:H = 1.008;  O = 15.999;  S = 32.06;  Cu = 63.546

16) What's the atomic number of sulfur-34 ? A) 34 B) 18 C) 16 17) In the formula of hydroxylapatite Cano(PO4)6(OH), determine the number of each kind of atom, Ca, O, H, P: A) Ca – 10; O – 8; H – 2; P - 6 с) Са — 10; О —12;B Н — 2;B Р - 6 в) Cа — 10; О — 26;B Н — 23B Р - 6 D) Ca – 10; O – 26; H – 2; P - 1 18) Which element is represented by the chemical symbol TI ? A) tantalum B) thorium C) thallium 19) The fact that water is 11.2 % hydroen and 88.8 % oxygen by mass regardless of its origin is an example of B) law of conservation of mass C) law of definite proportions A) Dalton's atomic theory

What is the relative abundance of isotope A?

what is the mass percentage of water in Zn(NO3)2*6H2O?

Predict the chemical formula for the ionic compoundformed by (a) Ca2+ and Br-, (b) K+ and CO32-, (c) Al3+ andCH3COO-, (d) NH4+ and SO42-, (e) Mg2+ and PO43-.

5 & 6 &7 plz

A mass spectrometer is being used to separate common oxygen-16 from the much rarer oxygen-18, taken from a sample of old glacial ice. (The relative abundance of these oxygen isotopes is related to climatic temperature at the time the ice was deposited.) The ratio of the masses of these two ions is 16 to 18, the mass of oxygen-16 is 2.66 ✕ 10−26 kg, and they are singly charged and travel at 7.40 ✕ 106 m/s in a 1.40 T magnetic field. What is the separation (in m) between their paths when they hit a target after traversing a semicircle?

11. Write the symbol for each of the following ions: (a) the ion with a 1+ charge, atomic number 55, and mass number 133 (b) the ion with 54 electrons, 53 protons, and 74 neutrons (c) the ion with atomic number 15, mass number 31, and a 3- charge (d) the ion with 24 electrons, 30 neutrons, and a 3+ charge

Give the preferred names for the following compounds. (a)    KBr(b)    Ba(NO3)2(c)    Li2S(d)    Na3PO4(e)    Al2(CO3)3(f)    SO3(g)    S2Cl2(h)    ZnI2