Chemistry Videos Search Your Question Skip to Videos All Videos AP Chem Subatomic Particles Chemical Reactions Aqueous Solutions Covalent Bonds Gases Thermochemistry Thermodynamics A 5.00-g sample of aluminum pellets (specific heat capacity = 0.89 J/°C · g) and a 10.00-g sample of Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below. A 130.2 gram sample of an unknown substance MM = 189.50 g/mol is cooled from Calculate the molar heat of fusion of this substance in kJ/mol. 300g of this unknown substance, with a molar mass of 180 g/mol, gives off 65 kJ of energy as it freezes. Calculate the work energy, w, gained or lost by the system when a gas expands from 20 L to 35 L Imagine a reaction that results in a change in both volume and temperature, as shown in the diagram below. Which compound below could have a zero dipole moment? What is the hybridization on the N atom in NO2- and in NO3-? Which drawing best represents hydrogen bonding? The orbital hybridization on the central carbon atom in CH3CCH is Use the data given below to construct a Born Haber cycle to determine the heat of formation of KCl. In how many sigma bonds does the highlighted atom participate What is the hybridization of the central atom in the tetrachloroiodide ICl4- anion? A chemist measures out 0.60 g of MgBr2 into a 100 ml flask. Find the molarity of Br- in solution. A chemist must prepare 575. mL of 203. μM aqueous magnesium fluoride (MgF2) working solution. She'll do this by pouring out some 549 How to find the molar mass of a diprotic acid mixed with NaOH in a titration experiment. How many grams of sulfur form when 37.4 g of water form? A sample of calcium fluoride was decomposed into the constituent elements If the sample produced 29 Find the atomic mass of Ag given the two isotopes Which has more S by mass: 1 gram of MgS or 1 gram of Na2S? The first ionization of a halogen atom X is represented by the equation below. When two equal charges q1 and q2 are separated by a distance r, the repulsive force between the Determine the limiting reactant LR and the mass in g of nitrogen that can be formed from 50 0 g N2O4 How many moles of oxygen are formed when 58.6 g of KNO3 decomposes according to the following A 14.01 g sample of N2 reacts with 3.02 g of H2 to form ammonia (NH3). A chemist prepares a solution of magnesium bromide MgBr2 by measuring AP Chemistry Unit 1 Sections 1.5 and 1.6 Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose C6H12O6 and oxygen O2 gas. Calculate Calculate the number of oxygen atoms in a 150.0 g sample of forsterite (Mg2SiO4). Compound A reacts with Compound B to form only one product, Compound C, and it's known the usual per AP Chem 1.4 Mixture Problems AP Chemistry Unit 1 Sections 1.3 and 1.4 AP Chemistry Unit 1 Sections 1.1 and 1.2 AP Chemistry Unit 1 Sections 1.1 and 1.2 Aqueous hydrochloric acid (HCl) will react with solid sodium hydroxide (NaOH) to produce aqueous sodium chloride (NaCl) Nitric acid is often manufactured from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming of natural gas Aqueous sulfurous acid (H₂SO₃) and aqueous sodium chloride are formed by the reaction of aqueous hydrochloric acid (HCl) A penny has a mass of 2.50 g and the Moon has a mass of 7.35×1022 kg Determine the number of protons, neutrons, and electrons in the following: 25 X 12 What does "X" represent in the following symbol? 80 X 35 Determine the number of protons, neutrons, and electrons in the following: 40 X 18 What does "X" represent in the following symbol? 28 X 14 How many protons (p) and neutrons (n) are in an atom of calcium-46? How many electrons are in the ion, P3-? How many protons (p), neutrons (n), and electrons (e) are in a neutral atom of iodine-125? Which of the species below has 28 protons and 26 electrons? The solid compound, NH4NO3, contains How many electrons are in the ion, CO32-? What type of bonding is found in the compound PCl5? What is the identity of element Q if the ion Q2+ contains 10 electrons? How many electrons are in the ion, Zn2+? How many moles and how many atoms of zinc are in a sample weighing 34.9 g? A student weighs out 14.9 mg of vanadium. How many moles are in the sample? What is the mass of one atom of the element hydrogen? Magnesium has three naturally occurring isotopes. One has an isotopic abundance of 78.99% and a mass of 23.985042 amu, and the second one has an isotopic abundance of 10.00% and a mass of 24.985837 One isotope has an abundance of 57.3% and an isotopic mass of 120.904 amu. Based on these data, what is the mass of the other isotope? One has an abundance of 37.4% and an isotopic mass of 184.953 amu, and the other has an abundance of 62.6% and a mass of 186.956 amu. What is the atomic weight of the element? How many electrons are in a neutral atom of iodine-131? What is the chemical symbol for an atom that has 29 protons and 36 neutrons? Boron-9 can be represented as A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 45.0 g of calcium fluroride? If 5.98 g of sodium react with water to form 0.26 g of hydrogen and 10.40 g of sodium hydroxide, what mass of water was consumed in the reaction? Methane and oxygen react to form carbon dioxide and water. What mass of water is formed if 3.2 g of methane reacts with 12.8 g of oxygen to produce 8.8 g of carbon dioxide?
