There are 2 unshared pair(s) around the central atom, so the geometry of the H_(2)O molecule is bent B. The Lewis diagram for BeBr_(2) Is: :Br-Bo-Br: The electron-pair geometry around the Be atom in BeBr_(2) is square There are square unshared pair(s) around the central atom, so the geometry of the BeBr_(2) molecule is square

The pH of a fruit juice is 3.3. Find the hydronium ion concentration, $[H_{3}O^{+}]$ of the juice. Use the formula $pH=-log[H_{3}O^{+}]$ The hydronium ion concentration $[H_{3}O^{+}]$ is approximately $\square $ moles per liter. (Use scientific notation. Use the multiplication symbol in the math palette as needed. Round to the nearest tenth as needed.)

Which is evidence that a chemical reaction has likely occurred? a liquid slowly losing volume the formation of a precipitate boiling water releasing steam a change in the shape of a solid

68. Which gas law describes the behavior of gases using the variables: temperature, volume , pressure and number of moles? A.Avogadro's law C.Ideal gas law B. Combined gas law D.Boyle's law 69. 2-methyl-1 -butene is one of the isomers of $C_{5}H_{10}$ Which of the following is the CORRECT structural formula of this isomer? A $CH_{3}\\ CH_{3}-C=CH-CH_{3}$ C. $CH_{3}\\ CH_{3}-CH-CH=CH_{2}$ B. $CH_{3}-CH=CH-CH_{2}-CH_{3}$ $CH_{3}\\ CH_{3}-CH_{2}-C=CH_{2}$ 70. Which of the following organic compounds is used for the production of $1,$ 2-ethanediol? A. Ethyne C. Ethene B. Ethanol D. Ethane 71. Which of the following is the main constituent of natural gas? A. Propane C. Ethane B. Methane D. Butane 72. In order to avoid the decrease in quality of some clothes after washing with water, which of the following chemicals is used for dry cleaning? A. $C_{2}H_{4}$ C. $CH_{4}$ B. $C_{2}Cl_{4}$ D. $CH_{2}Cl_{2}$ 73. Which type of glass is made by heating a mixture of silica, sodium carbonate and limestone? A. Pyrex C. Quartz B. Soda-lime D.Borosilicate

The test tube for Benedict's test is placed in a beaker of hot water over a Bunsen burner flame. What is the purpose of this step? Select an answer and submit. For keyboard navigation use the up/down arrow keys to select an answer. a The water is needed to produce the color change b The reaction requires heat to observe any color change C . The powder does not dissolve unless it is warm

Multiple Answer 1 point Select ALL true statements about buffers and buffer systems. The bicarbonate buffer system involves bicarbonate ions when buffering strong acids and bases. The protein buffer system involves charged regions of lipids toto buffer acids and bases. The fastest buffer systems in tl ne body are chemical buffer systems. The phosphate buffer system involves a phosphate molecule to buffer strong acids or bases in body cells. Abuffer is a chemical substance that helps maintain a relatively constant pHin a solution.

Use the References to access important values if needed for this question. Please note that "geometry"refers to the molecular or ionic geometry. In the VSEPR model the geometry of the regions defined by the electron pairs in the valence shell of an atom is called the electron- pair geometry. A. The Lewis diagram for $H_{2}O$ is: $H-\ddot {O}-H$ The electron-pair geometry around the 0 atom in $H_{2}O$ is $\square $ There are $\square $ unshared pair(s) around the central atom, so the geometry of the $H_{2}O$ molecule is $\square $

63. In which of the following is the type of natural resource and the given example COR REC TLY paired? A. Non-Renewable Resources; animal wool B. Non-Renewable Resources;water C. Renewable resources; copper D. Renewable resources:crops 64.Which of the following compound is a Bronsted-Lowry base? A. HCI B. $H_{2}S$ C. $BF_{3}$ D. $NH_{3}$ 65. Which statement below CORRECTLY distinguishes redox and non-redox reactions? A. Oxidation number remains the same in both redox and non-redox reactions. B. Acid-base reactions can be considered as both redox and non-redox reactions. Electrons are transferred in redox reactions but not in non-redox reactions. D. Reduction occurs in redox reactions and oxidation takes place in non- redox reactions. 66. Given the reaction $C(s)+CO_{2}(g)\rightleftharpoons 2CO(g)$ What is the equilibrium constant expression for the reaction? A. $\frac {[CO]^{2}}{[C]}$ $\frac {[CO]^{2}}{[C][CO_{2}]}$ B. $\frac {\vert C\Vert CO_{2}\vert }{\vert CO\vert ^{2}}$ D. $\frac {[CO]^{2}}{[CO_{2}]}$ 67. Which of the following pair of substances can be considered as examples of the liquid state of matter at room temperature and I atm pressure? A. Water and mercury C.Carbon and mercury Carbon and carbon monoxide D.Water and carbon dioxide

Which is an example of a chemical reaction? paper folded into tiny pieces paper burned and turned into smoke paper soaked in water paper shredded and turned into pulp

Did you report your data to the correct number of significant figures? Mass filter paper (g) .21 $Mass\quad filter\quad paper\quad +\quad precipitate\quad (g)$ 1.97 Calculated Observed mass calcium carbonate $(g)$ 1.76 Identify limiting reactant Sodium carbona Expected mass calcium carbonate $(g)$ $\square $ Percent yield $(\% )$ How to calculate theoretical yield and percent vield