{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Chapter 1+ Objectives

# Chapter 1+ Objectives - Chapter 1 Objectives Significant...

This preview shows pages 1–4. Sign up to view the full content.

Chapter 1 – Objectives Significant Figures: - All nonzero nu m b ers are significant ( 234 = 3 sig fig) - Zero’s b etwe en nonzero nu m b ers are significant ( 1006 = 4 sig fig) - Zero’s in front are NOT significant (0.00 5 = 1 sig fig) - Zero’s at th e e nd are significant (0.00 500 = 5 sig fig) - Ambiguous Sig Fig ie. 200, 50 = uncertain; zero could be intended as a significant figure, or it might just be there as a placeholder * To correct, write as scientific notation: 200 = 2 x 10^2 Multiplying/Dividing Sig Figs : look for least significant figure (6.22 cm x 5.2 cm = 34.43492 cm^2) = 34 cm^2 *Rounding: greater or equal to 5, round up less than 5, round down Addition/Subtraction: least significant figure + one space after decimal! 89.932 g 2.907 ergs - 1.1 g - 0.120 ergs (Only has 2 sig figs + 1) 90.432 g 1.977 ergs 90.4 g 1.98 ergs Example: 90.4 g x 9 = has 3 significant figures, any number without unit measure is infinitely significant Celsius and Kelvin Degrees: - To convert b etwe en Celsius an d Kelvin: Kelvin = Celsius + 273.0 Exam ple: Convert 25.0°C to Kelvin 25.0 + 273.0 = 298.0 K Convert 375 K to d egrees Celsius 375.0 – 273.0 = 102 °C

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Convert -50 ° C to Kelvin.  (That's minus 50)    -50.0 +  273 =  223 K Chapter 2 – Objectives Law of constant composition -   States that the composition of a substance is always the same, regardless of how the   substance w   or where the substance is found. *So, whenever we talk about water, we know that there are 2 atoms of hydrogen and 1 atom of oxygen in a   of water. Substance Formula Composition Properties water 2 atoms of hydrogen, 1 atom of oxygen  Clear, colorless, homogeneous liquid that is good for human consumption  hydrogen peroxide 2 atoms of hydrogen, 2 atoms of oxygen Clear, colorless, homogeneous liquid that is considered harmful if consumed by humans (poisonous). Law of Conservation of Matter : - The total mass of materials present after a chemical reaction is the same as the total mass pr   before the action. Mass is always the same and does not change.  Write a word equation: hydrogen +  oxygen  water  Write the masses of each substance given in the question 4 g ? 36 g
Use the law of conservation of mass (mass of reactants =  mass of products)  4 +  ? =  36 Solve to find the missing value  ? =  36 - 4 ? =  32 So 32 grams of oxygen were used Law of Multiple Proportions : - If two elements A and B combine to form more than one compound, the masses of B that com   with the given mass of A are in the ratio of small whole numbers. Cathode Ray Tube : - Discovered the electron.  - The cathode ray tube was an idea to study electrical discharge through partially evacuated tu   the tube, electrons move from the negative electrode (cathode) to the positive electrode (ano   The cathode rays originate from the negative plate on the left and are accelerated toward the   positive plate, which has a hole in its center. A beam of electrons passes through the hole and

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}