An analytical chemist measures the amount of Elements E, and E, in four samples of an unknown Substance mass mass sample of E, of E2 1 8.9 g 20.3 g It's known that X contains no elements other than E, and E,. 5.8 g 13.2 g 3 4.2 g 9.7 g 4 8.5 g 19.4 g Using this information, answer the questions in the table below. O pure substance Is Xa pure substance or a mixture? mixture If you don't have enough information to decide, choose can't decide. O (can't decide) If you said X is a pure substance, calculate the mass of Element E, the analytical chemist would find in a new 10.0 g sample of X. Round your answer to 2 significant digits.

An analytical chemist measures the amount Elements E₁ and E₂ in four samples of an unknown Substance X: mass mass sample of E₁ of E₂ 12.1 g 13.9 g 11.3 g 12.7 g 13.6 g 15.4 g 6.6 g 7.5 g Using this information, answer the questions in the table below. 1 2 3 4 It's known that X contains no elements other than E, and E₂. Is X a pure substance or a mixture? If you don't have enough information to decide, choose can't decide. If you said X is a pure substance, calculate the mass of Element E, the analytical chemist would find in a new 10.0 g sample of X. Round your answer to 2 significant digits. O pure substance O mixture O (can't decide) 0 X S s

2.09 mol L 502.8 mol 0.45 L 78.1 X 2.70 L = mol L = X 83. L = 0 mol. mol 0 L mol

On the planet Kracalac, in another solar system, argon has three naturally occurring isotopes as follows:      Isotope                         Mass (amu)                              Natural Abundance (%)      Argon-36                     35.968                                     10.65      Argon-38                     37.963                                     15.15      Argon-40                     39.962                                     74.20   What is the average atomic mass of argon on Kracalac?

One mole of calcium contains____calcium atoms. a)6.022x1023 b)40 c)20 d)1.20 x1024

What is a mole? How is the mole concept useful in chemical calculations?

Given these masses of elements found in a sample of a compound: 15.27 grams Ca, 4.57 grams: C, and 18.28 grams 0. Calculate the percent composition by mass of calcium, Ca. Calculate the percent composition by mass of carbon, C. Calculate the percent composition by mass of oxygen, O.

Answer all the questions.

A sample of carbon weighting 1.48 g was burned in an excess of air. The mass of carbon dioxide, the sole product was 5.42 g. In a second experiment 11.62 g of carbon dioxide was obtained. What mass of carbon was burned in the second experiment?

An element's percentage of the total mass in a compound containing the element. A law stating that when two elements (A and B) form two compounds, the masses of element B that combine with one gram of element A can be expressed as a ratio of small whole numbers. A chemical formula that show the simplest whole 1. Empirical formula number ratio of atoms in the compound. 2. Molecular formula A law stating that all samples of a given compound have the same 3. Law of Definite Proportions 4. Law of Multiple Proportions proportions of their constituent elements. 5. Law of Conservation of Mass A law stating that matter is neither created nor 6. Mass percent composition destroyed in a chemical reaction. 7. Molar mass The mass in grams of one mole of atoms in an 8. Constant mass clement. A chemical formula that shows the actual number of atoms of cach element in a moleculc of a compound. The mass obtained at the end of an experimcnt by weighing the product. rehcating and weighing again to…