【单选题】
计算<img class="kfformula" src="20200624/1592993098219071.png" data-latex="{71gC1}_{2}" width="79" height="31"/>所含原子数为( )<img class="kfformula" src="20200624/1592993098786896.png" data-latex="{N}_{A}" width="43" height="33"/>。
【单选题】
已知<img class="kfformula" src="20190809/1565322050560879.png" data-latex="A\left ( {0,-2} \right )"/>,<img class="kfformula" src="20190809/1565322050489966.png" data-latex="B\left ( {x,6} \right )"/>的中点坐标为<img class="kfformula" src="20190809/1565322050782302.png" data-latex="\left ( {-1,y} \right )"/>,则<img class="kfformula" src="20190809/1565322050701271.png" data-latex="x"/>,<img class="kfformula" src="20190809/1565322050277662.png" data-latex="y"/>的值分别为( )
①
<img class="kfformula" src="20190809/1565322050358526.png" data-latex="x=-4,y=-2"/>
②
<img class="kfformula" src="20190809/1565322050607462.png" data-latex="x=2,y=4"/>
③
<img class="kfformula" src="20190809/1565322050656212.png" data-latex="x=-4,y=25"/>
④
<img class="kfformula" src="20190809/1565322050205695.png" data-latex="x=-2,y=2"/>
【单选题】
有0.1mol/L<img class="kfformula" src="20200707/1594087695131974.png" data-latex="{Na}_{2}{SO}_{4}" width="77" height="30"/>溶液300mL,0.1mol/L<img class="kfformula" src="20200707/1594087695248793.png" data-latex="{MgSO}_{4}" width="70" height="30"/>溶液200mL和0.1mol/L<img class="kfformula" src="20200707/1594087695350060.png" data-latex="{Al}_{2}{({SO}_{4})}_{3}" width="83" height="31"/>溶液100mL,这三种溶液中硫酸根离子物质的量浓度之比是( )。
【单选题】
设<img class="kfformula" src="20200706/1594009368539359.png" data-latex="{N}_{A}" width="57" height="28"/>为阿伏加德罗常数的值,现有0.3mol/L<img class="kfformula" src="20200624/1592993842192203.png" data-latex="{K}_{2}{SO}_{4}" width="51" height="31"/> 溶液,1L溶液中钾离子有( )<img class="kfformula" src="20200624/1592993842591471.png" data-latex="{N}_{A}" width="57" height="34"/>个。
【单选题】
<img class="kfformula" src="20200629/1593405073701497.png" data-latex="{^{40}_{19}X}与{^{40}_{20}Y}互为(\, \, \, )。" width="219" height="37"/>
【单选题】
等差数列<img class="kfformula" src="20190809/1565317844150977.png" data-latex="\left \{ {{a}_{n}} \right \} "/>的首项<img class="kfformula" src="20190809/1565317844698638.png" data-latex="{a}_{1}=-2"/>,<img class="kfformula" src="20190809/1565317844536248.png" data-latex="{S}_{3}=3"/>,那么( )
①
<img class="kfformula" src="20190809/1565317844862924.png" data-latex="d=3"/>
②
<img class="kfformula" src="20190809/1565317844935823.png" data-latex="d=2"/>
③
<img class="kfformula" src="20190809/1565317844903124.png" data-latex="d=-2"/>
④
<img class="kfformula" src="20190809/1565317844953331.png" data-latex="d=-3"/>
【单选题】
要证明某溶液中不含<img class="kfformula" src="20200623/1592889822902078.png" data-latex="{Fe}^{3+}" width="72" height="34"/>,而含有<img class="kfformula" src="20200623/1592889822256510.png" data-latex="{Fe}^{2+}" width="64" height="39"/>,进行如下实验操作时最佳顺序为()。①加入少量氯水②加入少量<img class="kfformula" src="20200623/1592889822977069.png" data-latex="{KMnO}_{4}" width="109" height="37"/>溶液③加入少量KSCN溶液
【单选题】
已知<img class="kfformula" src="20190809/1565317530438878.png" data-latex="a,b,c"/>是公比为2的等比数列,则<img class="kfformula" src="20190809/1565317530533557.png" data-latex="\frac {{b}^{2}} {ac}" width="74" height="64"/>等于( )
①
<img class="kfformula" src="20190809/1565317530127108.png" data-latex="\frac {1} {2}"/>
②
<img class="kfformula" src="20190809/1565317530414229.png" data-latex="1"/>
③
<img class="kfformula" src="20190809/1565317530771921.png" data-latex="\frac {1} {8}"/>
④
<img class="kfformula" src="20190809/1565317530451678.png" data-latex="\frac {1} {4}"/>
【单选题】
下列污染现象主要与<img class="kfformula" src="20200629/1593429156221829.png" data-latex="{NO}_{2}" width="40" height="25"/>有关的是()。
【单选题】
设<img class="kfformula" src="20200624/1592994530966484.png" data-latex="{N}_{A}" width="49" height="27"/>为阿伏加德罗常数的值,现有0.3mol/L<img class="kfformula" src="20200624/1592994530304513.png" data-latex="{K}_{2}{SO}_{4}" width="61" height="30"/>溶液,2L溶液中钾离子的浓度为( )mol/L。