VincenTragosta - Tanya, Jawab, dan Belajar Tanpa Batas Logo

Questions in chemistry

[Terjawab] A chemist needs to know the mass of a sample of [tex]$MgCl _2$[/tex] to 5 significant digits. He puts the sample on a digital scale. This is what the scale shows: 0 0 4 0 7 If this measurement is precise enough for the chemist, round it to 5 significant digits. Otherwise, press the "No solution" button.

[Terjawab] Count the significant digits in each of these measurements: | measurement | number of significant digits | | :---------------------- | :----------------------------- | | [tex]$4.3 \times 10^{-3} mL$[/tex] | $\square$ | | [tex]$72700 . kg$[/tex] | $\square$ | | 0.005100 J | $\square$ | | [tex]$-6.0 \times 10^{-1} kJ / mol$[/tex] | $\square$ |

[Terjawab] Fill in the missing part of the student's equation: $\frac{(1.69 \square)(\frac{1 mL}{10^{-3} L})}{(81.19 \frac{g}{mol})}=20.8 \frac{mol}{L}$

[Terjawab] Count the significant digits in each of these measurements: | measurement | number of significant digits | | ----------- | ----------------------------- | | [tex]$4.3 \times 10^{-3} mL$[/tex] | | | [tex]$72700 . kg$[/tex] | | | 0.005100 J | | | [tex]$-6.0 \times 10^{-1} kJ / mol$[/tex] | |

[Terjawab] What is the formula for magnesium phosphide? MgP $Mg _3 P _2$ $Mg _3\left( PO _4\right)_2$ $Mg _3\left( PO _3\right)_2$

[Terjawab] An organic chemist measures the temperature T of a solution in a reaction flask. Here is the result: T = 141.0 °C Convert T to SI units. Round your answer to 3 significant figures.

[Terjawab] A chemical reaction is described by the following equation: [tex]Mg(OH)_2(aq)+2 HCl_{(aq)} \rightarrow MgCl_2(aq)+2 H_2 O_{(l)}[/tex] What type of reaction is this? Which of the statements below best describes this reaction? A. One compound breaks down into two or more substances. B. Two or more substances combine to form one compound. C. A hydrocarbon combines with oxygen to form carbon dioxide and water. D. One of the elements in a compound is replaced. E. Two compounds swap "partner" elements with each other.

[Terjawab] How many protons are in this sodium ion? ${}_{11}^{23} Na^{+}$

[Terjawab] A student sets up and solves the following equation to solve a problem in solution stoichiometry. Fill in the missing part of the student's equation. [tex](0.20 L)\left(\frac{1 mL}{10^{-3} L}\right)(0.60 \square)\left(\frac{1 kg}{10^3 g}\right)=0.12 kg[/tex]

[Terjawab] What is the formula for copper(II) oxide? A. [tex]$CuCO _4$[/tex] B. [tex]$Cu _2 O$[/tex] C. CuO D. [tex]$CO _2$[/tex]