<span>iron gets hotter before copper.</span>
The patch area in square kilometers is 1.59*10⁻⁹ km₂
Why?
This is an unit conversion problem. We have to convert from cm² to km². We can do that by knowing that there are 100 cm in 1 m, and 1000 m in 1 km, so 100000 cm=1km. Knowing that we can apply the following conversion factor:
Now to convert this value to scientific notation, we have to move the decimal point to the right until we get a whole number, and the exponent of the number 10 is going to be the number of spaces we moved to the right (negative), so the final answer is:
Have a nice day!
#LearnwithBrainly
Answer:
Its a or d if im stupid my b
Explanation:
X(OH)₂ + 2HCl = XCl₂ + 2H₂O
n{X(OH)₂}=m{X(OH)₂}/M{X(OH)₂}
n(HCl)=c(HCl)v(HCl)
n{X(OH)₂}=n(HCl)/2
m{X(OH)₂}/M{X(OH)₂}=c(HCl)v(HCl)/2
M{X(OH)₂}=2m{X(OH)₂}/{c(HCl)v(HCl)}
M{X(OH)₂}=2*8.65/{2.50*56.9*10⁻³}=121.6 g/mol
M(OH)=17.0 g/mol
M(X)=121.6-17.0*2=87.6 g/mol ⇒ X=Sr, strontium
Sr(OH)₂ + 2HCl = SrCl₂ + 2H₂O
<span> It is a little hard to explain step-by-step what to do so I hope you can follow what to do by looking at how I arranged the equations.
2 H2O(g) --------------------------> 2 H2O(l) -88
2 H2 + O2 ----------------------------> 2 H2O(g) -484
C + O2 ----------------------------> CO2 -393.5
CH4 -------------------------------> C + 2 H2 + 74.8
________________________________________...
CH4 + 2 O2 ---------------------> CO2 + 2 H2O -890.6 kJ
Once you cancel out the substances that appear BOTH on the left AND the right of the arrows you are left with your net equation. </span>
