Hello Camkirkland,
I think that you are trying to balance this equation.
In order to balance a chemical equation, the numbers of atoms of each element must be equal on both sides of the equation.
In this particular equation, the answer would be (2) HBr + (1) Mg(OH)2 ---> (1) MgBr2 + (2) H2O.
Hope this answers your question!
Mg reaction with O₂ gas will produce MgO so the equation will be
2Mg+O₂⇒2MgO. (You have to find the equation in order two figure out the number of moles of O₂ that will react with 1 mole of MgO).
The first step is to find the number of moles of Mg in 4.03g of Mg. You can do this by dividing 4.03g Mg by its molar mass (which is 24.3g/mol) to get 0.1658mol Mg. Then you have to find the number of moles of O₂ that will react with 0.1658mol Mg. To do this you need to use the fact that 1mol O₂ will react with 2mol Mg (this reatio is from the chemical equation) so you have to multiply 0.1658mol Mg by (1mol O₂)/(2mol Mg) to get 0.0829mol O₂. From here you would usually use PV=nRT and solve for V However, the question tells us that we are at STP, that means you can use the fact that 22.4L of gas is 1 mol of gas at STP. Using that information we can find the volume of O₂ gas by mulitlying 0.0829mol O₂ by 22.4L/mol to get 1.857L which equals 1857mL.
therefore, 1857mL of O₂ gas will react with 4.03g of Mg.
I hope this helps. Let me know in the comments if anything is unclear.
Answer:
B. 1-heptene
Explanation:
The 1-HEPTENE molecule contains a total of 20 bond(s) There are 6 non-H bond(s), 1 multiple bond(s), 4 rotatable bond(s) and 1 double bond(s).
Charles law gives the relationship between temperature and volume of gases. It states that the volume of gas is directly proportional to temperature at constant pressure.
V / T = k
where V - volume and T - temperature in Kelvin and k - constant

where parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
T1 - 20 °C + 273 = 293 K
substituting these values in the equation

T = 586 K
temperature in celsius = 586 K - 273 = 313 °C
new temperature is 313 °C